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/board/broadcom/bcm96753ref/Kconfig b/board/broadcom/bcm96753ref/Kconfig
new file mode 100644
index 0000000..479e790
--- /dev/null
+++ b/board/broadcom/bcm96753ref/Kconfig
@@ -0,0 +1,16 @@
+if TARGET_BCM96753REF
+
+config SYS_VENDOR
+	default "broadcom"
+
+config SYS_BOARD
+	default "bcm96753ref"
+
+config SYS_CONFIG_NAME
+	default "broadcom_bcm96753ref"
+
+endif
+
+config TARGET_BCM96753REF
+	bool "Support Broadcom bcm96753ref"
+	depends on ARCH_BCM6753