mips: bpf: fix encoding bug for mm_srlv32_op

mips: bpf: fix encoding bug for mm_srlv32_op

For micro-mips, srlv inside POOL32A encoding space should use 0x50
sub-opcode, NOT 0x90.

Some early version ISA doc describes the encoding as 0x90 for both srlv and
srav, this looks to me was a typo. I checked Binutils libopcode
implementation which is using 0x50 for srlv and 0x90 for srav.

v1->v2:
  - Keep mm_srlv32_op sorted by value.

Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Song Liu <songliubraving@fb.com>
Fixes: f31318fdf324 ("MIPS: uasm: Add srlv uasm instruction")
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: daniel@iogearbox.net
Cc: ast@kernel.org
Cc: netdev@vger.kernel.org
Cc: oss-drivers@netronome.com
Cc: linux-mips@vger.kernel.org