x86: Change MMIO addr in readN(addr)/writeN(addr, val) to pointer

On x86, change the type of the address parameter in
read8()/read16/read32()/write8()/write16()/write32() to be a
pointer, instead of unsigned long.

Change-Id: Ic26dd8a72d82828b69be3c04944710681b7bd330
Signed-off-by: Kevin Paul Herbert <kph@meraki.net>
Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Reviewed-on: http://review.coreboot.org/7784
Tested-by: build bot (Jenkins)
diff --git a/src/northbridge/intel/gm45/raminit_receive_enable_calibration.c b/src/northbridge/intel/gm45/raminit_receive_enable_calibration.c
index 5130b59..62be05e 100644
--- a/src/northbridge/intel/gm45/raminit_receive_enable_calibration.c
+++ b/src/northbridge/intel/gm45/raminit_receive_enable_calibration.c
@@ -147,7 +147,7 @@
 	MCHBAR32(mchbar) |=  (1 << 9);
 
 	/* Read from this channel. */
-	read32(raminit_get_rank_addr(channel, 0));
+	read32((u32 *)raminit_get_rank_addr(channel, 0));
 
 	mchbar = 0x14b0 + (channel * 0x0100) + ((7 - lane) * 4);
 	return MCHBAR32(mchbar) & (1 << 30);