Revert "Remove code that enables/disables VMX in coreboot on chromebooks."

The MSR for VMX can start with a random value and needs to be
cleared by coreboot. I am reverting this change, as
it handles almost everything and doing a follow-on change to fix
the improper clearing of the MSR.

Change-Id: Ibad7a27b03f199241c52c1ebdd2b6d4e81a18a4e
Signed-off-by: Marc Jones <marc.jones@se-eng.com>
Reviewed-on: http://review.coreboot.org/1793
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

src/cpu/intel/model_206ax/finalize.c

@@ -43,6 +43,7 @@ static void msr_set_bit(unsigned reg, unsigned bit)
 
 void intel_model_206ax_finalize_smm(void)
 {
+	msr_set_bit(IA32_FEATURE_CONTROL, 0);
 	msr_set_bit(MSR_PMG_CST_CONFIG_CONTROL, 15);
 
 	/* Lock AES-NI only if supported */