staging: comedi: Kconfig: update CONFIG_AMPLC_DIO200_PCI help text

After splitting support for PCI cards out of the "amplc_dio200" module
into "amplc_dio200_pci", the help text needs updating.

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