arm64: fix config and supported.conf for MTD devices on NXP boards
    
    References: bsc#1167137
    
    Get rid of CONFIG_MTD_PHYSMAP_COMPAT and enable CONFIG_MTD_PHYSMAP_OF.
    Compat maps of zero length (CONFIG_MTD_PHYSMAP_LEN=0x0) doesn't make
    sense and driver initialization is bound to fail.
    
    Update supported.conf to include required modules.
    
    Signed-off-by: Mian Yousaf Kaukab <yousaf.kaukab@suse.com>