Commit 710224fa2750cf449c02dd115548acebfdd2c86a adds dma_set_coherent_mask()
back but doesn't export the symbol, leading to build failures of modules
like this :

ERROR: "dma_set_coherent_mask" [drivers/usb/host/ehci-hcd.ko] undefined!

Reported-by: Martin Michlmayr <tbm@cyrius.com>
Tested-by: Martin Michlmayr <tbm@cyrius.com>
Cc: <stable@kernel.org>
Signed-off-by: Arnaud Patard <arnaud.patard@rtp-net.org>

Index: linux-2.6.36/arch/arm/mach-ixp4xx/common-pci.c
===================================================================
--- linux-2.6.36.orig/arch/arm/mach-ixp4xx/common-pci.c	2010-11-07 14:55:33.540059282 +0100
+++ linux-2.6.36/arch/arm/mach-ixp4xx/common-pci.c	2010-11-07 20:27:04.572059692 +0100
@@ -510,6 +510,7 @@ int dma_set_coherent_mask(struct device
 
 	return -EIO;
 }
+EXPORT_SYMBOL(dma_set_coherent_mask);
 
 EXPORT_SYMBOL(ixp4xx_pci_read);
 EXPORT_SYMBOL(ixp4xx_pci_write);