Update the MikroTik CRS305-1G-4S flash layout to support redundant UBI partitions. Additionally enable the UBI commands in crs305-1g-4s_defconfig. Signed-off-by: Luka Kovacic <luka.kovacic@sartura.hr> Cc: Luka Perkov <luka.perkov@sartura.hr> Cc: Jakov Petrina <jakov.petrina@sartura.hr> Reviewed-by: Stefan Roese <sr@denx.de>