[ARM] Export ixp42xx_pci_read/write so PCI driver modules load

Originally found by Thomas Winkler <winkler@iti.tu-graz.ac.at>
Signed-off-by: Deepak Saxena <dsaxena@plexity.net>

arch/arm/mach-ixp4xx/common-pci.c

@@ -540,4 +540,6 @@ pci_set_consistent_dma_mask(struct pci_dev *dev, u64 mask)
 EXPORT_SYMBOL(pci_set_dma_mask);
 EXPORT_SYMBOL(pci_dac_set_dma_mask);
 EXPORT_SYMBOL(pci_set_consistent_dma_mask);
+EXPORT_SYMBOL(ixp4xx_pci_read);
+EXPORT_SYMBOL(ixp4xx_pci_write);