soc/intel/skylake: Clean up CPU code

Use header (soc/intel/common/block/include/intelblocks/msr.h) for
MSR macros

Change-Id: I401b92cda54b6140f2fe23a6447dad89879a5ef0
Signed-off-by: Subrata Banik <subrata.banik@intel.com>
Reviewed-on: https://review.coreboot.org/18554
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

src/soc/intel/skylake/cpu.c

@@ -409,7 +409,7 @@ static int get_cpu_count(void)
 	int num_threads;
 	int num_cores;
 
-	msr = rdmsr(CORE_THREAD_COUNT_MSR);
+	msr = rdmsr(MSR_CORE_THREAD_COUNT);
 	num_threads = (msr.lo >> 0) & 0xffff;
 	num_cores = (msr.lo >> 16) & 0xffff;
 	printk(BIOS_DEBUG, "CPU has %u cores, %u threads enabled.\n",