ARM: convert PCI defines to variables

Convert PCIBIOS_MIN_IO and PCIBIOS_MIN_MEM to variables to allow
multi-platform builds. This also removes the requirement for a platform to
have a mach/hardware.h.

The default values for i/o and mem are 0x1000 and 0x01000000, respectively.
Per Arnd Bergmann, other values are likely to be incorrect, but this commit
does not try to address that issue.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
diff --git a/arch/arm/mach-pxa/cm-x2xx-pci.c b/arch/arm/mach-pxa/cm-x2xx-pci.c
index 1afc0fb..4eb7660 100644
--- a/arch/arm/mach-pxa/cm-x2xx-pci.c
+++ b/arch/arm/mach-pxa/cm-x2xx-pci.c
@@ -125,6 +125,9 @@
 {
 	pr_info("Initializing CM-X2XX PCI subsystem\n");
 
+	pcibios_min_io = 0;
+	pcibios_min_mem = 0;
+
 	__raw_writel(0x800, IT8152_PCI_CFG_ADDR);
 	if (__raw_readl(IT8152_PCI_CFG_DATA) == 0x81521283) {
 		pr_info("PCI Bridge found.\n");