staging: comedi: remove private header comedi_pci.h

Remove the private header, comedi_pci.h, by moving the two
helper functions into divers.c and providing the prototypes
in comedidev.h.

This allows the comedi_pci_enable/disable helper functions
to be shared instead of having an inline version in every
comedi pci driver.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Cc: Mori Hess <fmhess@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>