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/mainboard/intel/truxton/mptable.c b/src/mainboard/intel/truxton/mptable.c
index 9ad6ea6..87b40dd 100644
--- a/src/mainboard/intel/truxton/mptable.c
+++ b/src/mainboard/intel/truxton/mptable.c
@@ -70,7 +70,7 @@
 	mptable_write_buses(mc, NULL, &bus_isa);
 
 	/* IOAPIC handling */
-	smp_write_ioapic(mc, 0x8, 0x20, IO_APIC_ADDR);
+	smp_write_ioapic(mc, 0x8, 0x20, VIO_APIC_VADDR);
 
 	mptable_add_isa_interrupts(mc, bus_isa, 0x8, 0);