nb/intel/sandybridge: Drop pch.h from sandybridge.h

Include pch.h in the source files instead in sandybridge.h.

Tested on Lenovo T520 (Intel Sandy Bridge).
Still boots to OS, no errors visible in dmesg.

Change-Id: I9e5b678e979a8d136d8d00b49486d0a882f77d81
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32065
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>

src/northbridge/intel/sandybridge/raminit.c

@@ -29,6 +29,7 @@
 #include <mrc_cache.h>
 #include <southbridge/intel/bd82x6x/me.h>
 #include <southbridge/intel/common/smbus.h>
+#include <southbridge/intel/bd82x6x/pch.h>
 #include <cpu/x86/msr.h>
 
 #include "raminit_native.h"