cpu/intel/haswell: Set LT_LOCK_MEMORY MSR on finalize step

This is a security lock and is required for TXT, among other things.

Tested on Asrock B85M Pro4, still boots.

Change-Id: I7b2e8a60ce92cbf523c520be0b365f28413b9624
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/44884
Reviewed-by: Michael Niewöhner
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/cpu/intel/haswell/finalize.c

@@ -6,4 +6,6 @@
 
 void intel_cpu_haswell_finalize_smm(void)
 {
+	/* Lock memory configuration to protect SMM */
+	msr_set_bit(MSR_LT_LOCK_MEMORY, 0);
 }