cpu/x86/smm: Define APM_CNT_NOOP_SMI

Old (!PARALLEL_MP) cpu bringup uses this as the first
control to do SMM relocation.

Change-Id: I4241120b00fac77f0491d37f05ba17763db1254e
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/42617
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>

src/include/cpu/x86/smm.h

@@ -17,6 +17,7 @@
 #define SMM_SAVE_STATE_BEGIN(x) (SMM_ENTRY_OFFSET + (x))
 
 #define APM_CNT		0xb2
+#define APM_CNT_NOOP_SMI	0x00
 #define APM_CNT_CST_CONTROL	0x85
 #define APM_CNT_PST_CONTROL	0x80
 #define APM_CNT_ACPI_DISABLE	0x1e