target/arm: Convert T16, Change processor state

Add a check for ARMv6 in trans_CPS.  We had this correct in
the T16 path, but had previously forgotten the check on the
A32 and T32 paths.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190904193059.26202-58-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>