comedi: Humusoft MF634 and MF624 DAQ cards driver

This patch adds Comedi driver for Humusoft MF634 (PCIe) and
MF624 (PCI) data acquisition cards. The legacy card Humusoft
MF614 is not supported. More info about the cards may be found
at http://humusoft.cz/produkty/datacq/
The driver was tested with both cards. Everything seems to work
properly. Just the basic functionality of the card (DIO, ADC, DAC)
is supported by this driver.

Signed-off-by: Rostislav Lisovy <lisovy@gmail.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>