libpayload: Initial ARMv7 port

This compiles, but it's not tested yet.

Change-Id: I2f73a814649aa36c39af3e77cefd8a968671f5c0
Signed-off-by: Stefan Reinauer <reinauer@google.com>
Reviewed-on: http://review.coreboot.org/2035
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

payloads/libpayload/Config.in

@@ -67,16 +67,21 @@ choice
         prompt "Target Architecture"
         default ARCH_X86
 
+config ARCH_ARMV7
+        bool "ARMv7"
+        help
+          Support the x86 architecture
+
+config ARCH_POWERPC
+        bool "PowerPC"
+        help
+	  Support the PowerPC architecture
+
 config ARCH_X86
         bool "x86"
         help
           Support the x86 architecture
 
-config TARGET_POWERPC
-        bool "PowerPC"
-        help
-	  Support the PowerPC architecture
-
 endchoice
 
 config MEMMAP_RAM_ONLY
@@ -198,12 +203,12 @@ config VIDEO_CONSOLE
 
 config VGA_VIDEO_CONSOLE
 	bool "VGA video console driver"
-	depends on VIDEO_CONSOLE
+	depends on ARCH_X86 && VIDEO_CONSOLE
 	default y
 
 config GEODELX_VIDEO_CONSOLE
 	bool "Geode LX video console driver"
-	depends on VIDEO_CONSOLE
+	depends on ARCH_X86 && VIDEO_CONSOLE
 	default n
 
 config COREBOOT_VIDEO_CONSOLE
@@ -234,10 +239,12 @@ menu "Drivers"
 
 config PCI
 	bool "Support for PCI devices"
+	depends on ARCH_X86 # for now
 	default y
 
 config NVRAM
 	bool "Support for reading/writing NVRAM bytes"
+	depends on ARCH_X86 # for now
 	default y
 
 config RTC_PORT_EXTENDED_VIA
@@ -258,6 +265,7 @@ config RTC_PORT_EXTENDED_VIA
 
 config SPEAKER
 	bool "Support for PC speaker"
+	depends on ARCH_X86
 	default y
 
 config STORAGE