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/southbridge/sis/sis966/lpc.c b/src/southbridge/sis/sis966/lpc.c
index a61883b..c9f1ff6 100644
--- a/src/southbridge/sis/sis966/lpc.c
+++ b/src/southbridge/sis/sis966/lpc.c
@@ -59,13 +59,13 @@
 static void lpc_common_init(device_t dev)
 {
 	uint8_t byte;
-	uint32_t ioapic_base;
+	void *ioapic_base;
 
 	/* IO APIC initialization */
 	byte = pci_read_config8(dev, 0x74);
 	byte |= (1<<0); // enable APIC
 	pci_write_config8(dev, 0x74, byte);
-	ioapic_base = pci_read_config32(dev, PCI_BASE_ADDRESS_1); // 0x14
+	ioapic_base = (void *)pci_read_config32(dev, PCI_BASE_ADDRESS_1); // 0x14
 
 	setup_ioapic(ioapic_base, 0); // Don't rename IO APIC ID
 }