staging: dgnc: delete dgnc_pci.h

Move the few #defines we actually use into the dgnc_driver.c file, no
need to have a .h file for a driver that is only used by a single .c
file.

Cc: Lidza Louina <lidza.louina@gmail.com>
Cc: Mark Hounschell <markh@compro.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>