staging: comedi: addi_apci_1710: only pci bar 2 is used

This driver used to be tied to the addi-data common code which
always saved the start address of pci bars 0, 1, 2, and 3 for
use by the driver. This driver only uses pci bar 2.

Remove all the non-used pci bars and move the saving of pci bar
2 so it occurs right after the pci device is enabled.

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