tifm: use module_pci_driver

tifm_7xx1_init and tifm_7xx1_exit with module_init and module_exit calls
can be replaced with the module_pci_driver call, as they are similar
to what module_pci_driver does

Signed-off-by: Devendra Naga <devendra.aaru@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>