FindMPI: do not detect `-framework` as a compile flag

MPICH 3.4.2 now reports `-framework OpenCL` as one of its compilation
flag. The compile flag extraction is seeing it as a generic `-f` flag
and misses its argument. This ends up with a compile option of
`-framework` which eats the next flag (and may be very important).

It does not seem that passing `-framework` as a link flag is necessary
at this time, so that is being actively ignored for now.

Fixes: #22555