staging: comedi: addi_apci_1564: simplify the PCI bar reading and don't read the unused bars

This driver only uses PCI bar 0 (devpriv->i_IobaseAmcc), and PCI bar 1
(dev->iobase), don't bother reading the unused PCI bars.

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