nb/intel/gm45/raminit: Use CxDRT*_MCHBAR instead of magic numbers

This is hopefully more readable.

TEST=Build lenovo/x200 with and without this patch (using make
BUILD_TIMELESS=1), compare build/coreboot.rom, notice no differences.

Change-Id: I079d5353633a3d58ce0e5e616f3fad687a064d65
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Reviewed-on: https://review.coreboot.org/23709
Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/northbridge/intel/gm45/raminit.c b/src/northbridge/intel/gm45/raminit.c
index af5faf0c..08f954d 100644
--- a/src/northbridge/intel/gm45/raminit.c
+++ b/src/northbridge/intel/gm45/raminit.c
@@ -1804,10 +1804,12 @@
 	/* Perform receive-enable calibration. */
 	raminit_receive_enable_calibration(timings, dimms);
 	/* Lend clock values from receive-enable calibration. */
-	MCHBAR32(0x1224) = (MCHBAR32(0x1224) & ~(0xf0)) |
-			   ((((MCHBAR32(0x121c) >> 7) - 1) & 0xf) << 4);
-	MCHBAR32(0x1324) = (MCHBAR32(0x1324) & ~(0xf0)) |
-			   ((((MCHBAR32(0x131c) >> 7) - 1) & 0xf) << 4);
+	MCHBAR32(CxDRT5_MCHBAR(0)) =
+		(MCHBAR32(CxDRT5_MCHBAR(0)) & ~(0xf0)) |
+		((((MCHBAR32(CxDRT3_MCHBAR(0)) >> 7) - 1) & 0xf) << 4);
+	MCHBAR32(CxDRT5_MCHBAR(1)) =
+		(MCHBAR32(CxDRT5_MCHBAR(1)) & ~(0xf0)) |
+		((((MCHBAR32(CxDRT3_MCHBAR(1)) >> 7) - 1) & 0xf) << 4);
 
 	/* Perform read/write training for high clock rate. */
 	if (timings->mem_clock == MEM_CLOCK_1067MT) {