Add instructions of SLR, SSRO and SRO opcode format.

Signed-off-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>

Reviewed-by: Richard Henderson <rth@twiddle.net>
Message-id: 1409572800-4116-15-git-send-email-kbastian@mail.uni-paderborn.de
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>