x86: Add Intel Tangier support

Add Intel Tangier SoC support.

Intel Tangier SoC is a core part of Intel Merrifield platform. For
example, Intel Edison board is based on such platform.

The patch is based on work done by the following people (in alphabetical
order):
	Aiden Park <aiden.park@intel.com>
	Dukjoon Jeon <dukjoon.jeon@intel.com>
	eric.park <eric.park@intel.com>
	Fabien Chereau <fabien.chereau@intel.com>
	Scott D Phillips <scott.d.phillips@intel.com>
	Sebastien Colleur <sebastienx.colleur@intel.com>
	Steve Sakoman <steve.sakoman@intel.com>
	Vincent Tinelli <vincent.tinelli@intel.com>

Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Signed-off-by: Vincent Tinelli <vincent.tinelli@intel.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 0cd981e..5c8dc82 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -114,6 +114,7 @@
 source "arch/x86/cpu/qemu/Kconfig"
 source "arch/x86/cpu/quark/Kconfig"
 source "arch/x86/cpu/queensbay/Kconfig"
+source "arch/x86/cpu/tangier/Kconfig"
 
 # architecture-specific options below