staging/comedi: Add macro for registering a comedi PCMCIA driver

This patch introduces a new macro 'module_comedi_pcmcia_driver'
for comedi PCMCIA drivers which do not do anything special in module
init/exit. This eliminates a lot of boilerplate.

Adapted from 'module_comedi_pci_driver'

Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>