Add .h files for samsung exynos 5250

Per a conversation with Stefan, these chip-dependent files are moved
to the src tree, in the manner of other chips (north and southbridge).

Change-Id: I12645ba05eb241eda200ed06cb633541a6a98119
Signed-off-by: Ronald G. Minnich <rminnich@gmail.com>
Signed-off-by: David Hendricks <dhendrix@chromium.org>
Signed-off-by: Stefan Reinauer <stepan@coresystems.de>
Reviewed-on: http://review.coreboot.org/1925
Tested-by: build bot (Jenkins)

src/Kconfig

@@ -204,6 +204,8 @@ config ARCH_X86
 	bool
 	default n
 
+# Warning: The file is included whether or not the if is here.
+# but the if controls how the evaluation occurs.
 if ARCH_X86
 source src/arch/x86/Kconfig
 endif