arm: switch to GENERIC_PCI_IOMAP

arm copied pci_iomap from generic code, probably to avoid
pulling the rest of iomap.c in.  Since that's in
a separate file now, we can reuse the common implementation.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
diff --git a/arch/arm/include/asm/io.h b/arch/arm/include/asm/io.h
index 065d100..9275828 100644
--- a/arch/arm/include/asm/io.h
+++ b/arch/arm/include/asm/io.h
@@ -27,6 +27,7 @@
 #include <asm/byteorder.h>
 #include <asm/memory.h>
 #include <asm/system.h>
+#include <asm-generic/pci_iomap.h>
 
 /*
  * ISA I/O bus memory addresses are 1:1 with the physical address.
@@ -306,7 +307,6 @@
 
 struct pci_dev;
 
-extern void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen);
 extern void pci_iounmap(struct pci_dev *dev, void __iomem *addr);
 
 /*