ARM: kill off __mem_pci

__mem_pci is only used to enable readl/writel and friends. Just condition
this on readl being defined and remove all the __mem_pci defines.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Lennert Buytenhek <kernel@wantstofly.org>
Cc: Imre Kaloz <kaloz@openwrt.org>
Cc: Krzysztof Halasa <khc@pm.waw.pl>
Cc: Nicolas Pitre <nico@fluxnic.net>
Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: Colin Cross <ccross@android.com>
Cc: Olof Johansson <olof@lixom.net>
Cc: Stephen Warren <swarren@nvidia.com>

arch/arm/mach-ixp4xx/include/mach/io.h

@@ -39,11 +39,7 @@ extern int ixp4xx_pci_write(u32 addr, u32 cmd, u32 data);
  *    but in some cases the performance hit is acceptable. In addition, you
  *    cannot mmap() PCI devices in this case.
  */
-#ifndef	CONFIG_IXP4XX_INDIRECT_PCI
-
-#define __mem_pci(a)		(a)
-
-#else
+#ifdef	CONFIG_IXP4XX_INDIRECT_PCI
 
 /*
  * In the case of using indirect PCI, we simply return the actual PCI