staging: comedi: das08: Support multiple PCI card types in future

Rename the existing board entry named "das08" for the PCI-DAS08 board to
"pci-das08".  Add a new wildcard board entry called "das08" that will
match any supported PCI board.  If 'dev->board_ptr' points to the
wildcard board entry in the ->attach() routine, it will be replaced with
a supported PCI board entry if there are any (taking into account the
bus and slot specified by the device config options passed in to the
function).

Split the code that finds a matching PCI device into a new function
das08_find_pci().

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