MIPS: Correctly define DBSHFL type instruction opcodes.

MIPS: Correctly define DBSHFL type instruction opcodes.

DSHD was incorrectly classified as being BSHFL, and DSHD was missing
altogether.

Signed-off-by: David Daney <david.daney@cavium.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16366/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>