Support NUMAKER_PFM_NUC472

1.  Support Nuvoton targets:
    -   NUMAKER_PFM_NUC472
2.  Change storage to NUSD (SD card in SDIO bus mode) from SD (SD card SPI bus mode)
    (1) Add COMPONENT_NUSD.lib.
    (2) Add component NUSD (target.components_add).
    (3) Change default BlockDevice to NUSD:
        Override BlockDevice::get_default_instance (nusd.provide-default-blockdevice).
        Required since mbed-cloud-client 2.1.0 (arm_uc_blockdevice_ext) or in:
        mbed-bootloader/modules/storage/pal-blockdevice/source/arm_uc_pal_blockdevice_mbed.cpp
    (4) Enable kvstore with blockdevice type being "other".
        i)  Override get_other_blockdevice() (nusd.provide-kvstore-other-blockdevice).
        ii) Configure storage type to "FILESYSTEM".
        iii)Configure file system type to "LITTLE".
        vi) Configure block device type to "other".
        v)  Configure external size to 64MiB, which cannot overlap with update-client.
            storage-address/update-client.storage-size.

Author: ccli8

README.md

@@ -26,6 +26,7 @@ Board                          |  Connectivity     | Storage for credentials and
 `Embedded Planet EP_AGORA`          | Cellular          | SPIF                    | Build-only
 `ST NUCLEO_H743ZI2`                 | Ethernet          | Internal Flash          | Build-only
 `ST NUCLEO_L4R5ZI`                  | Wi-Fi ESP8266     | Internal Flash          | Build-only
+`Nuvoton NUMAKER_PFM_NUC472`        | Ethernet          | SD card (NUSD)          | Build-only
 `Nuvoton NUMAKER_PFM_M487`          | Ethernet          | SD card (NUSD)          | Build-only
 `Nuvoton NUMAKER_IOT_M487`          | Wi-Fi ESP8266     | SD card (NUSD)          | Build-only
 `Seeed ARCH_MAX`                    | Ethernet          | SD card                 | Build-only

bootloader/mbed-bootloader-nuc472-block_device-kvstore-v4.1.0.bin

@@ -184,6 +184,31 @@
             "esp8266.cts"                               : "PA_11",
             "esp8266.provide-default"                   : true
         },
+        "NUMAKER_PFM_NUC472": {
+            "target.extra_labels_add"                   : ["PSA"],
+            "target.network-default-interface-type"     : "ETHERNET",
+            "target.bootloader_img"                     : "bootloader/mbed-bootloader-nuc472-block_device-kvstore-v4.1.0.bin",
+            "bootloader-size"                           : "(64*1024)",
+            "target.header_offset"                      : "0x12000",
+            "target.app_offset"                         : "0x12400",
+            "target.components_add"                     : ["NUSD"],
+            "nusd.provide-default-blockdevice"          : true,
+            "nusd.provide-kvstore-other-blockdevice"    : true,
+            "update-client.bootloader-details"          : "0x0",
+            "update-client.application-details"         : "0x12000",
+            "update-client.storage-address"             : "(1024*1024*64)",
+            "update-client.storage-size"                : "((MBED_ROM_START + MBED_ROM_SIZE - APPLICATION_ADDR) * MBED_CONF_UPDATE_CLIENT_STORAGE_LOCATIONS)",
+            "update-client.storage-locations"           : 1,
+            "mbed-cloud-client.update-storage"          : "ARM_UCP_FLASHIAP_BLOCKDEVICE",
+            "storage.storage_type"                      : "FILESYSTEM",
+            "storage_filesystem.filesystem"             : "LITTLE",
+            "storage_filesystem.blockdevice"            : "other",
+            "storage_filesystem.internal_base_address"  : "(MBED_ROM_START + MBED_BOOTLOADER_SIZE)",
+            "storage_filesystem.rbp_internal_size"      : "(2*4*1024)",
+            "storage_filesystem.external_base_address"  : "(0x0)",
+            "storage_filesystem.external_size"          : "(1024*1024*64)",
+            "target.macros_add"                         : ["MBEDTLS_USER_CONFIG_FILE=\"mbedTLSConfig_mbedOS_SW_TRNG_PSA.h\"", "MBEDTLS_PSA_CRYPTO_C", "MBEDTLS_ENTROPY_NV_SEED", "PAL_USE_HW_TRNG=0"]
+        },
         "NUMAKER_PFM_M487": {
             "target.extra_labels_add"                   : ["PSA"],
             "target.network-default-interface-type"     : "ETHERNET",