soc/intel/xeon_sp: Move read_msr_ppin() to common util.c

Move CPX and SKX read_msr_ppin() to common util.c file.
Update drivers/ocp/smbios #include to match.

Change-Id: I4c4281d2d5ce679f5444a502fa88df04de9f2cd8
Signed-off-by: Marc Jones <marcjones@sysproconsulting.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/46479
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Jay Talbott <JayTalbott@sysproconsulting.com>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

src/drivers/ocp/dmi/smbios.c

@@ -9,7 +9,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <soc/soc_util.h>
-#include <soc/cpu.h>
+#include <soc/util.h>
 #include <smbios.h>
 
 #include "ocp_dmi.h"