[ARM] Fix pci export warnings

Remove duplicate PCI exports from ixp4xx machine class.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

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

@@ -532,8 +532,6 @@ pci_set_consistent_dma_mask(struct pci_dev *dev, u64 mask)
 	return -EIO;
 }
 
-EXPORT_SYMBOL(pci_set_dma_mask);
-EXPORT_SYMBOL(pci_set_consistent_dma_mask);
 EXPORT_SYMBOL(ixp4xx_pci_read);
 EXPORT_SYMBOL(ixp4xx_pci_write);