[POWERPC] Make isa_mem_base common to 32 and 64 bits

This defines isa_mem_base on both 32 and 64 bits (it used to be 32 bits
only).  This avoids a few ifdef's in later patches and potentially can
allow support for VGA text mode on 64 bits powerpc.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/kernel/pci-common.c

@@ -50,6 +50,9 @@ static DEFINE_SPINLOCK(hose_spinlock);
 /* XXX kill that some day ... */
 static int global_phb_number;		/* Global phb counter */
 
+/* ISA Memory physical address */
+resource_size_t isa_mem_base;
+
 
 struct pci_controller *pcibios_alloc_controller(struct device_node *dev)
 {

arch/powerpc/kernel/pci_32.c

@@ -32,7 +32,6 @@
 #endif
 
 unsigned long isa_io_base     = 0;
-unsigned long isa_mem_base    = 0;
 unsigned long pci_dram_offset = 0;
 int pcibios_assign_bus_offset = 1;
 

include/asm-powerpc/io.h

@@ -50,15 +50,16 @@ extern int check_legacy_ioport(unsigned long base_port);
 #define PCI_DRAM_OFFSET	pci_dram_offset
 #else
 #define _IO_BASE	pci_io_base
-#define _ISA_MEM_BASE	0
+#define _ISA_MEM_BASE	isa_mem_base
 #define PCI_DRAM_OFFSET	0
 #endif
 
 extern unsigned long isa_io_base;
-extern unsigned long isa_mem_base;
 extern unsigned long pci_io_base;
 extern unsigned long pci_dram_offset;
 
+extern resource_size_t isa_mem_base;
+
 #if defined(CONFIG_PPC32) && defined(CONFIG_PPC_INDIRECT_IO)
 #error CONFIG_PPC_INDIRECT_IO is not yet supported on 32 bits
 #endif