add ramdisk image generation binary
drivers/exfat: add Samsung's open source exFat module version 1.2.4

Signed-off-by: Paul Reioux <reioux@gmail.com>
drivers/Makefile: add exFat support

Signed-off-by: Paul Reioux <reioux@gmail.com>
Fix kconfig warnings
replace full FSync() with FPut_Light() for slightly better io write speeds while maintaining sync
DTS/DTB fixups