bcm96753ref: add initial support

This add the initial support of the broadcom reference
board bcm96753ref with a bcm6753 SoC.

This board has 1 GB of RAM, 256 MB of flash (nand),
2 USB port, 1 UART, and 4 ethernet ports.

Signed-off-by: Philippe Reynes <philippe.reynes@softathome.com>
diff --git a/arch/arm/dts/Makefile b/arch/arm/dts/Makefile
index 960f1a9..e53ad53 100644
--- a/arch/arm/dts/Makefile
+++ b/arch/arm/dts/Makefile
@@ -1104,6 +1104,9 @@
 dtb-$(CONFIG_ARCH_BCM68360) += \
 	bcm968360bg.dtb
 
+dtb-$(CONFIG_ARCH_BCM6753) += \
+	bcm96753ref.dtb
+
 dtb-$(CONFIG_ARCH_BCM6858) += \
 	bcm968580xref.dtb