bcm2836 SoC support (used in Raspberry Pi 2 model B)

The bcm2835 and bcm2836 are essentially identical, except:
- The CPU is an ARM1176 v.s. a quad-core Cortex-A7.
- The physical address of many IO controllers has moved.

Rather than introducing a whole new bcm2836 value for $(SOC) or $(ARCH),
update the existing bcm2835 code to handle the minor differences, and
plumb it into the ARMv7 CPU architecture.

Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>
diff --git a/arch/arm/include/asm/arch-bcm2835/gpio.h b/arch/arm/include/asm/arch-bcm2835/gpio.h
index db42896..c8ef8f5 100644
--- a/arch/arm/include/asm/arch-bcm2835/gpio.h
+++ b/arch/arm/include/asm/arch-bcm2835/gpio.h
@@ -1,6 +1,7 @@
 /*
  * Copyright (C) 2012 Vikram Narayananan
  * <vikram186@gmail.com>
+ * (C) Copyright 2012,2015 Stephen Warren
  *
  * SPDX-License-Identifier:	GPL-2.0+
  */
@@ -8,7 +9,11 @@
 #ifndef _BCM2835_GPIO_H_
 #define _BCM2835_GPIO_H_
 
+#ifdef CONFIG_BCM2836
+#define BCM2835_GPIO_BASE		0x3f200000
+#else
 #define BCM2835_GPIO_BASE		0x20200000
+#endif
 #define BCM2835_GPIO_COUNT		54
 
 #define BCM2835_GPIO_FSEL_MASK		0x7