make the MIPS24k HWPMC support require hwpmc_mips24k as well as hwpmc.
make the MIPS24k HWPMC support require hwpmc_mips24k as well as hwpmc.

This way non-MIPS24k platforms (eg Octeon) can have separate PMC support.

Requested by:	juli

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase