uboot-phytec

Revert "fs: fat: support write with non-zero offset"

This reverts commit cb8af8af5ba03ae8e0a7315b66bfcc46d5c55627.

fatwrites after this patch corrupt images. A fatwrite followed by a
fatload and compare yields different data.

Reproduce it with:
=>fatwrite mmc 0 0x82000000 test_32M 0x2000000;
=>fatload mmc 0 0x84000000 test_32M;
=>cmp.b 82000000 84000000 0x2000000

Result:
byte at 0x821260b2 (0xbf) != byte at 0x841260b2 (0xbd)
Total of 1204402 byte(s) were the same

Updating images in the SD card with fatwrite corrupts the images in the
board and it no longer boots. Revert this commit until a more stable
solution is found.

Signed-off-by: Faiz Abbas <faiz_abbas@ti.com>