Convert pci_module_init() to pci_register_driver().

Signed-off-by: Richard Knutsson <ricknu-0@student.ltu.se>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>