nb/intel: Replace remaining BAR accessors

These changes are not reproducible for some reason.

Change-Id: I43b445b8af8871db87fb86747db8a35cec75716a
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/51867
Reviewed-by: Nico Huber <nico.h@gmx.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/northbridge/intel/sandybridge/northbridge.c b/src/northbridge/intel/sandybridge/northbridge.c
index 6e95461..bd4d107 100644
--- a/src/northbridge/intel/sandybridge/northbridge.c
+++ b/src/northbridge/intel/sandybridge/northbridge.c
@@ -210,8 +210,6 @@
 
 	const u8 stepping = cpu_stepping();
 
-	u32 reg32;
-
 	/* Steps prior to DMI ASPM */
 	if (is_sandy) {
 		dmibar_clrsetbits32(0x250, 7 << 20, 2 << 20);
@@ -224,10 +222,7 @@
 	}
 
 	if (!is_sandy || stepping >= SNB_STEP_D1) {
-		reg32 = dmibar_read32(0x1f8);
-		reg32 &= ~(1 << 26);
-		reg32 |= (1 << 16);
-		dmibar_write32(0x1f8, reg32);
+		dmibar_clrsetbits32(0x1f8, 1 << 26, 1 << 16);
 
 		dmibar_setbits32(0x1fc, 1 << 12 | 1 << 23);