MIPS: CM: Fix GCR_Cx_CONFIG PVPE mask

MIPS: CM: Fix GCR_Cx_CONFIG PVPE mask

The PVPE (or PVP in >= CM3) field is 10 bits wide, but the mask
previously only covered the bottom 9 bits. Extend the mask to cover all
10 bits of the field.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Patchwork: https://patchwork.linux-mips.org/patch/11206/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>