MIPS: cpu: Alter MIPS_CPU_* definitions to fill gap

MIPS: cpu: Alter MIPS_CPU_* definitions to fill gap

The MIPS_CPU_* definitions accidentally missed bits 27..30 when
MIPS_CPU_EVA was added, and further definitions have continued from
there.

Shift all the definitions since MIPS_CPU_EVA right by 4 so there are no
gaps.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/10044/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>