arm: mvebu: Add DB-XC3-24G4XG board

The DB-XC3-24G4XG is a switch development board from Marvell. It can
either use and external CPU card such as the db-88f6820-amc or the
internal CPU that is integrated into the switch.

Add support for running U-Boot on the internal CPU and enable the USB,
SPI and NAND peripherals. For now this needs the bin_hdr from the
Marvell U-Boot for this board.

Signed-off-by: Chris Packham <judge.packham@gmail.com>
Reviewed-by: Stefan Roese <sr@denx.de>
Signed-off-by: Stefan Roese <sr@denx.de>
diff --git a/board/Marvell/db-xc3-24g4xg/README b/board/Marvell/db-xc3-24g4xg/README
new file mode 100644
index 0000000..5e479b4
--- /dev/null
+++ b/board/Marvell/db-xc3-24g4xg/README
@@ -0,0 +1,4 @@
+To generate binary.0 from Marvell's bin_hdr.elf use the following command
+
+    arm-softfloat-linux-gnueabi-objcopy -S -O binary bin_hdr.elf \
+       board/Marvell/db-xc3-24g4xg/binary.0