staging: comedi: addi_common.h: rename boardinfo 'pc_DriverName'

Rename this CamelCase member of the boardinfo.

The comedi_device 'board_name' is set to this member during the (*auto_attach)
of the addi-data that still use this boardinfo drivers. For aesthetics, use
the dev->board_name instead of the boardinfo in the drivers.

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