We only use the IS_M() macro in two places, and it's a bit of a
namespace grab to put in cpu.h.  Drop it in favour of just explicitly
calling arm_feature() in the places where it was used.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NAlex Bennée <alex.bennee@linaro.org>
Message-id: 1485285380-10565-2-git-send-email-peter.maydell@linaro.org