media: imx477: Increase IMX477_VBLANK_MIN due to image corruption

The 4056x3040 mode appears to need more vertical blanking lines
than any other, leaving a black bar at the bottom of the image.

Increase IMX477_VBLANK_MIN from 4 to 48 to compensate. (It may be
possible to reduce it slightly further, but fix the regression
for now).

#7109

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>

Author: 6by9

drivers/media/i2c/imx477.c

@@ -72,7 +72,7 @@ MODULE_PARM_DESC(fstrobe_delay, "Set fstrobe delay from end all lines starting t
 
 /* V_TIMING internal */
 #define IMX477_REG_FRAME_LENGTH		CCI_REG16(0x0340)
-#define IMX477_VBLANK_MIN		4
+#define IMX477_VBLANK_MIN		48
 #define IMX477_FRAME_LENGTH_MAX		0xffdc
 
 /* H_TIMING internal */