arm: bcmbca: add bcm6858 SoC support under CONFIG_ARCH_BCMBCA

BCM6858 is a Broadcom B53 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_BCM6858 chip config and
CONFIG_ARCH_BCMBCA platform config.

This initial support includes a bare-bone implementation and the
original dts is updated with the one from linux next git repository.

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/arch/arm/mach-bcmbca/Makefile b/arch/arm/mach-bcmbca/Makefile
index 20f8275..c068094 100644
--- a/arch/arm/mach-bcmbca/Makefile
+++ b/arch/arm/mach-bcmbca/Makefile
@@ -15,4 +15,5 @@
 obj-$(CONFIG_BCM6813) += bcm6813/
 obj-$(CONFIG_BCM6846) += bcm6846/
 obj-$(CONFIG_BCM6856) += bcm6856/
+obj-$(CONFIG_BCM6858) += bcm6858/
 obj-$(CONFIG_BCM6878) += bcm6878/