[CORE] Add error codes VMM_EROFS, VMM_EBADMSG and VMM_EUCLEAN

Signed-off-by: Jimmy Durand Wesolowski <jimmy.durand-wesolowski@openwide.fr>
Signed-off-by: Anup Patel <anup@brainfault.org>
[DRIVERS] MTD port on Xvisor.

Signed-off-by: Jimmy Durand Wesolowski <jimmy.durand-wesolowski@openwide.fr>
Signed-off-by: Anup Patel <anup@brainfault.org>