staging: comedi: addi_apci_1500: set board_ptr before calling addi_auto_attach()

This driver only supports a single PCI device. If we set the
dev->board_ptr before calling addi_auto_attach() we remove
the need for the common code to search for the boardinfo.

Since the search is not done we can remove the unnecessary
board information from the comedi_driver.

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