arm: bcmbca: add bcm6855 SoC support under CONFIG_ARCH_BCMBCA

BCM6855 is a Broadcom ARM A7 based PON Gateway SoC. It is part of the
BCA (Broadband Carrier Access origin) chipset family. Like other
broadband SoC, this patch adds it under CONFIG_BCM6855 chip config and
CONFIG_ARCH_BCMBCA platform config.

This initial support includes a bare-bone implementation and dts with
CPU subsystem, memory and ARM PL101 uart. This SoC is supported in the
linux-next git repository so the dts and dtsi files are copied from linux.

The u-boot image can be loaded from flash or network to the entry point
address in the memory and boot from there to the console.

Signed-off-by: William Zhang <william.zhang@broadcom.com>
Reviewed-by: Philippe Reynes <philippe.reynes@softathome.com>
diff --git a/board/broadcom/bcmbca/Kconfig b/board/broadcom/bcmbca/Kconfig
index 7da9e95..5903a6a 100644
--- a/board/broadcom/bcmbca/Kconfig
+++ b/board/broadcom/bcmbca/Kconfig
@@ -86,6 +86,13 @@
 
 endif
 
+if TARGET_BCM96855
+
+config SYS_CONFIG_NAME
+	default "bcm96855"
+
+endif
+
 if TARGET_BCM96856
 
 config SYS_CONFIG_NAME