staging: comedi: das08.h: change description in copyright header comment

The copyright header comment includes a single-line description saying
it is for "das08.c" and "das08_cs.c".  However, it is also used by
"das08_isa.c" and "das08_pci.c".  Update the description to say it is
for common DAS08 support, similar to description in "das08.c" (the
common module for the DAS08 ISA/PCI/PCMCIA drivers).

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