M2354: Adjust TF-M configuration to fit AWS IoT

1.  In TF-M, enlarge ITS max asset number/size
    NOTE: RSA key size is larger
2.  In TF-M, enlarge mbedtls dedicated heap
    NOTE: RSA algorithm needs more memory.
    NOTE: psa_aead_decrypt() (for mbedtls_ssl_read()) needs memory proportional to data size.

Author: ccli8