dma-mapping: powerpc: use generic pci_set_dma_mask and pci_set_consistent_dma_mask

This converts powerpc to use the generic pci_set_dma_mask and
pci_set_consistent_dma_mask (drivers/pci/pci.c).

The generic pci_set_dma_mask does what powerpc's pci_set_dma_mask does.

Unlike powerpc's pci_set_consistent_dma_mask, the gneric
pci_set_consistent_dma_mask sets only coherent_dma_mask.  It doesn't work
for powerpc?  pci_set_consistent_dma_mask API should set only
coherent_dma_mask?

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Greg KH <greg@kroah.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>