spi-topcliff-pch: rename pch_spi_pcidev to pch_spi_pcidev_driver

Rename static struct pci_driver pch_spi_pcidev to
pch_spi_pcidev_driver to get rid of warnings from modpost checks.

Signed-off-by: Danny Kukawka <danny.kukawka@bisect.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>