staging: comedi: plx9080.h: correct LRNG_IO_MASK and LMAP_IO_MASK

For the PLX local address space range registers, LAS0RR and LAS1RR, bit
0 indicates whether the local address space will be mapped to memory
space or I/O space.  If mapped to I/O space, bit 1 must be set to 0, and
bits 31 to 2 form the address decoding mask, which should be -2^N mod
2^32 for a range of length 2^N.

The `LRNG_IO_MASK` macro is supposed to specify the address decoding
bits for I/O space.  It currently has the value `0xfffffffa`, but should
be `0xfffffffc`, or possibly `0xfffffffe` (it doesn't really matter,
since bit 1 is required to be set to 0).  Change it to `0xfffffffc`.

Similarly, for the PLX local address space local base address (remap)
registers, LAS0BA and LAS1BA, bits 31 to 2, masked with the
corresponding "range" register form the local base address for the local
address space.  The `LMAP_IO_MASK` macro is supposed to mask the valid
bits for I/O space.  Change its value from `0xfffffffa` to `0xfffffffc`
to match `LRNG_IO_MASK`.

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