x86: Move common PCH code into a common place

The SATA indexed register write functions are common to several Intel PCHs.
Move this into a common location.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/arch/x86/cpu/ivybridge/cpu.c b/arch/x86/cpu/ivybridge/cpu.c
index bb720ba..0f93905 100644
--- a/arch/x86/cpu/ivybridge/cpu.c
+++ b/arch/x86/cpu/ivybridge/cpu.c
@@ -21,6 +21,7 @@
 #include <asm/intel_regs.h>
 #include <asm/io.h>
 #include <asm/lapic.h>
+#include <asm/lpc_common.h>
 #include <asm/microcode.h>
 #include <asm/msr.h>
 #include <asm/mtrr.h>