target/mips: Fix MSA BZ/BNZ opcodes displacement

The PC offset is *signed*.

Cc: qemu-stable@nongnu.org
Reported-by: Sergey Evlashev <vectorchiefrocks@gmail.com>
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1624
Fixes: c7a9ef7 ("target/mips: Introduce decode tree bindings for MSA ASE")
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230914085807.12241-1-philmd@linaro.org>
(cherry picked from commit 04591b3)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

target/mips/tcg/msa.decode

@@ -31,8 +31,8 @@
 
 @lsa                ...... rs:5 rt:5 rd:5 ... sa:2 ......   &r
 @ldst               ...... sa:s10 ws:5 wd:5 .... df:2       &msa_i
-@bz_v               ...... ... ..    wt:5 sa:16             &msa_bz df=3
-@bz                 ...... ...  df:2 wt:5 sa:16             &msa_bz
+@bz_v               ...... ... ..    wt:5 sa:s16            &msa_bz df=3
+@bz                 ...... ...  df:2 wt:5 sa:s16            &msa_bz
 @elm_df             ...... .... ......    ws:5 wd:5 ......  &msa_elm_df df=%elm_df n=%elm_n
 @elm                ...... ..........     ws:5 wd:5 ......  &msa_elm
 @vec                ...... .....     wt:5 ws:5 wd:5 ......  &msa_r df=0