arm: mvebu: Add CRS305-1G-4S Bit board

MikroTik CRS305-1G-4S Bit board has a switch chip with an integrated
Marvell Prestera 98DX3236 CPU.

The Bit board variant is added, which has a bigger Macronix flash.

Add basic U-Boot, UART and Winbond SPI flash support.

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>
diff --git a/board/mikrotik/crs3xx-98dx3236/MAINTAINERS b/board/mikrotik/crs3xx-98dx3236/MAINTAINERS
index 127e0ea..d02584b 100644
--- a/board/mikrotik/crs3xx-98dx3236/MAINTAINERS
+++ b/board/mikrotik/crs3xx-98dx3236/MAINTAINERS
@@ -6,6 +6,9 @@
 
 CRS305-1G-4S BOARD
 M:	Luka Kovacic <luka.kovacic@sartura.hr>
+M:	Luka Perkov <luka.perkov@sartura.hr>
 S:	Maintained
 F:	configs/crs305-1g-4s_defconfig
+F:	configs/crs305-1g-4s-bit_defconfig
 F:	arch/arm/dts/armada-xp-crs305-1g-4s.dts
+F:	arch/arm/dts/armada-xp-crs305-1g-4s-bit.dts