staging/sep: use module_pci_driver macro

this driver duplicates the module_pci_driver code, so remove the
duplicated code and use module_pci_driver and also remove the
obvious comments about _init and _exit.

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