staging: comedi: daqboard2000: use pci_id_table 'driver_data'

staging: comedi: daqboard2000: use pci_id_table 'driver_data'

The driver's COMEDI "auto-attach" handler `db2k_auto_attach()` calls
`db2k_find_boardinfo()` to find an element of our board information
array `db2k_boardtypes[]` that matches the probed PCI device.  The
driver's PCI device table matches several boards in the DaqBoard/2000
series that match a single PCI vendor and device ID combination.
`db2k_find_boardinfo()` uses the probed PCI device's subvendor and
subdevice IDs to find the matching board information, returning `NULL`
for no match.

Change the driver's PCI device table `db2k_pci_table[]` to match
supported PCI vendor, device, subvendor and subdevice IDs, and set the
`.driver_data` member of each element to the index of the matching
element of `db2k_boardtypes[]`.  That index gets passed through to the
COMEDI auto-attach handler `db2k_auto_attach()`.  Use it to index
directly into `db2k_boardtypes[]` instead of calling
`db2k_find_boardinfo()` to find the match.
Use array index designators in the initializer of `db2k_boardtypes[]`.
Use enumerated constants defined by new type `enum db2k_boardids` to
name the board type indices.

The `id` member of `struct db2k_boardtype` is no longer used, so remove
it.  Also remove the subdevice ID macros `DB2K_SUBSYSTEM_IDS2` and
`DB2K_SUBSYSTEM_IDS4` as the subdevice IDs are now specified as numbers
in the PCI device table.  Remove `db2k_find_boardinfo()` as it is no
longer used.

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