target-tricore: add illegal opcode trap generation

Reviewed-by: Richard Henderson  <rth@twiddle.net>
Signed-off-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Message-Id: <1455889426-1923-4-git-send-email-kbastian@mail.uni-paderborn.de>
