disas: Remove target_words_bigendian() call in initialize_debug_target()

disas: Remove target_words_bigendian() call in initialize_debug_target()

All CPUClass implementating disas_set_info() must set the
disassemble_info::endian value.

Ensure that by setting %endian to BFD_ENDIAN_UNKNOWN before
calling the CPUClass::disas_set_info() handler, then asserting
%endian is not BFD_ENDIAN_UNKNOWN after the call.

This allows removing the target_words_bigendian() call in disas/.

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20250210212931.62401-11-philmd@linaro.org>