Random CRC failures for all eMMC SDR50/HS200/HS400 mode

The issue is reproduced locally on the TI EVM as well but only for HS400.

The local test setup is:

1) SBL NULL modified with the patch

The patch does the following:

• Enables MMCSD module in the SBL NULL sysconfig.
• Adds a BOOTLOADER instance for an image in eMMC at 0x0 offset.
• Integrates a test function, in the `main.c` file, designed to read the image in a loop for 25K times authenticating each time to make sure the data is read correctly.

2) The image in the eMMC at 0x0 offset is signed Linux Falcon appimage (~20MB).

3) The SBL NULL & Linux Appimage is flashed at 0x0 offset of OSPI & eMMC respectively.

4) The bootmode is OSPI & the EVM is kept on run.

5) The random resets are injected when the test function is executing in the loop reading & authenticating the image.

6) On certain reset cycles, the authentication for the very first read reports FAIL. The cause of the authentication failure is found to be CRC error while reading the image.

Observations:

• The issue is reproduced locally only with HS400 mode while customers reports it for all SDR50/HS200/HS400 modes.
• The issue is observed with both warm & cold resets done via the onboard switch button & relay respectively.
• The issue is reproduced only when resets are randomly hit during the loop reading & authenticating the image. If the resets are done after the test func is executed then there are no failures seen.