configs: cyclone5: Enable SPL FAT support

configs: cyclone5: Enable SPL FAT support

Enable support for FAT filesystem with SPL for CycloneV instead of raw
mode.

Recent changes breaks CycloneV MMC boot from raw mode, and so we are taking
this opportunity to migrate MMC boot mode to FAT as smaller OCRAM size is
required, as well as aligning MMC boot flow with our other devices.

Fixes: 2a00d73d081a1 ("spl: mmc: Try to clean up raw-mode options")

Signed-off-by: Alif Zakuan Yuslaimi <alif.zakuan.yuslaimi@altera.com>
Reviewed-by: Tien Fong Chee <tien.fong.chee@altera.com>