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