rename ARCH_BCM to ARCH_BCM_MOBILE (mach-bcm)

Currently ARCH_BCM has been used for Broadcom
Mobile V7 based SoCs. In order to allow other Broadcom
SoCs to also use mach-bcm directory and files, this patch
renames the original ARCH_BCM to ARCH_BCM_MOBILE, and
uses ARCH_BCM to define any Broadcom chip residing
in mach-bcm directory.

Signed-off-by: Christian Daudt <bcm@fixthebug.org>
Acked-by: Olof Johansson <olof@lixom.net>

Changes from v2:
 - switch ARCH_MULTIPLATFORM from select to depends
 - remove 'default y' from BCM_MOBILE

Changes from v1:
 - fix alpha ordering in dts/Makefile
 - break into 4 patches for separate subsys
diff --git a/arch/arm/configs/multi_v7_defconfig b/arch/arm/configs/multi_v7_defconfig
index f3935b4..24a36e3 100644
--- a/arch/arm/configs/multi_v7_defconfig
+++ b/arch/arm/configs/multi_v7_defconfig
@@ -6,6 +6,7 @@
 CONFIG_MACH_ARMADA_370=y
 CONFIG_MACH_ARMADA_XP=y
 CONFIG_ARCH_BCM=y
+CONFIG_ARCH_BCM_MOBILE=y
 CONFIG_GPIO_PCA953X=y
 CONFIG_ARCH_HIGHBANK=y
 CONFIG_ARCH_KEYSTONE=y