MIPS: Allow CPU specific overriding of CP0 hwrena impl bits.

Some CPUs have implementation dependent rdhwr registers.  Allow them
to be enabled on a per CPU basis.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2 files changed