MIPS: tlbex: Stop open-coding build_convert_pte_to_entrylo

Make use of build_convert_pte_to_entrylo in the RIXI cases within
build_update_entries rather than open-coding it 4 times.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
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/11214/


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