staging: comedi: amplc_dio200: add helper macros to check bus type

Add helper macro IS_ISA_BOARD(board) to check if the driver supports ISA
boards and this is an ISA board, and IS_PCI_BOARD(board) to check if the
driver supports PCI boards and this is a PCI board.

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