We don't implement very much of the GPTM TAR register, and what we
do is wrong. The "are we in RT mode?" field is in s->config, not
s->control. Correct this, use LOG_UNIMP rather than hw_error()
for the cases we don't support, and avoid an unlabelled fallthrough
that makes Coverity complain.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>