nb/intel/ironlake: Use `MSAC` definition

Tested with BUILD_TIMELESS=1, Packard Bell MS2290 remains identical.

Change-Id: I479fd701f992701584d77d43c5cd5910f5ab7632
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/45383
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
diff --git a/src/northbridge/intel/ironlake/raminit.c b/src/northbridge/intel/ironlake/raminit.c
index 0cefe4f..68eefec 100644
--- a/src/northbridge/intel/ironlake/raminit.c
+++ b/src/northbridge/intel/ironlake/raminit.c
@@ -3654,8 +3654,8 @@
 		MCHBAR16_OR(0x2c30, 0x200);
 		MCHBAR16(0x2c32) = 0x434;
 		MCHBAR32_AND_OR(0x2c44, 0, 0x1053687);
-		pci_read_config8(GMA, 0x62);	// = 0x2
-		pci_write_config8(GMA, 0x62, 0x2);
+		pci_read_config8(GMA, MSAC);	// = 0x2
+		pci_write_config8(GMA, MSAC, 0x2);
 		read8(DEFAULT_RCBA + 0x2318);
 		write8(DEFAULT_RCBA + 0x2318, 0x47);
 		read8(DEFAULT_RCBA + 0x2320);