staging: comedi: amplc_dio200: don't check bus-type in dio200_common_attach()

The "amplc_dio200" driver is going to be split into separate drivers for
ISA and PCI cards with a common module containing most of the code.  We
don't want the common module code to depend on whether ISA boards, PCI
boards, or both are supported.  Currently, `dio200_common_attach()` and
`dio200_detach()` optimize out the code to support a timer subdevice
when built to support ISA boards only.  Remove the `if (DO_PCI)` tests
which optimize out that code.  Unfortunately, this will expand the
module's code size for an ISA-only driver a bit.

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