target/tricore: Fix RRPW_DEXTR

target/tricore: Fix RRPW_DEXTR

if we used const16 == 0 we would crash qemu with the error:
../tcg/tcg-op.c:196: tcg_gen_shri_i32: Assertion `arg2 >= 0 && arg2 < 32' failed

This whole instruction can be handled by 'tcg_gen_extract2_tl' which
takes care of this special case as well.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Message-Id: <20230202120432.1268-6-kbastian@mail.uni-paderborn.de>
Signed-off-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>