nb/intel/sandybridge: add and use more MCHBAR register defines

Change-Id: Ie0a9be0899830a2bf9a994d10c417b0968d1cd47
Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/38010
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
diff --git a/src/northbridge/intel/sandybridge/raminit.c b/src/northbridge/intel/sandybridge/raminit.c
index c13ae37..0362330 100644
--- a/src/northbridge/intel/sandybridge/raminit.c
+++ b/src/northbridge/intel/sandybridge/raminit.c
@@ -101,9 +101,9 @@
 	u32 addr_decoder_common, addr_decode_ch[NUM_CHANNELS];
 	int i, refclk;
 
-	addr_decoder_common = MCHBAR32(0x5000);
-	addr_decode_ch[0] = MCHBAR32(0x5004);
-	addr_decode_ch[1] = MCHBAR32(0x5008);
+	addr_decoder_common = MCHBAR32(MAD_CHNL);
+	addr_decode_ch[0] = MCHBAR32(MAD_DIMM_CH0);
+	addr_decode_ch[1] = MCHBAR32(MAD_DIMM_CH1);
 
 	refclk = MCHBAR32(MC_BIOS_REQ) & 0x100 ? 100 : 133;