tile: switch to GENERIC_PCI_IOMAP

tile now has working stubs for ioport_map and ioremap
such that the generic pci_iomap will DTRT: cast to
pointer on memory and return NULL and log message on IO map.

Switch it over to GENERIC_PCI_IOMAP.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
diff --git a/arch/tile/Kconfig b/arch/tile/Kconfig
index 70a0de4..11270ca 100644
--- a/arch/tile/Kconfig
+++ b/arch/tile/Kconfig
@@ -321,6 +321,7 @@
 	bool "PCI support"
 	default y
 	select PCI_DOMAINS
+	select GENERIC_PCI_IOMAP
 	---help---
 	  Enable PCI root complex support, so PCIe endpoint devices can
 	  be attached to the Tile chip.  Many, but not all, PCI devices