spi: use module_pci_driver

This patch converts the drivers in drivers/spi/* to use module_pci_driver()
macro which makes the code smaller and a bit simpler.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

diff --cc drivers/spi/spi-dw-pci.c
Simple merge

diff --cc drivers/spi/spi-pxa2xx-pci.c
Simple merge