coresight tmc: Handle configuration types properly

Coresight SoC 600 defines a new configuration for TMC, Embedded Trace
Streamer (ETS), indicated by 0x3 in MODE:CONFIG_TYPE. This would break
the existing driver which will treat anything other than ETR/ETB as an
ETF. Fix the driver to check the configuration type properly and also
add a warning if we encounter an unsupported configuration (ETS).

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>