include/cpu/amd/msr: don't redefine the IA32_BIOS_SIGN_ID MSR

Change-Id: Iff19ae495fb9c0795dae4b2844dc8e0220a57b2c
Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/56310
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Marshall Dawson <marshalldawson3rd@gmail.com>

src/cpu/amd/pi/00730F01/update_microcode.c

@@ -78,7 +78,7 @@ static void apply_microcode_patch(const struct microcode *m)
 	printk(BIOS_DEBUG, "microcode: patch id to apply = 0x%08x\n",
 		m->patch_id);
 
-	msr = rdmsr(MSR_PATCH_LEVEL);
+	msr = rdmsr(IA32_BIOS_SIGN_ID);
 	new_patch_id = msr.lo;
 
 	if (new_patch_id == m->patch_id)