MIPS: Separate MAAR V bit into VL and VH for XPA

The MAAR V bit has been renamed VL since another bit called VH is added
at the top of the register when it is extended to 64-bits on a 32-bit
processor with XPA. Rename the V definition, fix the various users, and
add definitions for the VH bit. Also add a definition for the MAARI
Index field.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org