MIPS: asm: asm-eva: Introduce kernel load/store variants

Introduce new macros for kernel load/store variants which will be
used to perform regular kernel space load/store operations in EVA
mode.

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: <stable@vger.kernel.org> # v3.15+
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9500/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>