coresight: etm4x: Expose trcdevarch via sysfs

coresight: etm4x: Expose trcdevarch via sysfs

Expose the TRCDEVARCH register via the sysfs for component
detection. Given that the TRCIDR1 may not completely identify
the ETM component and instead need to use TRCDEVARCH, expose
this via sysfs for tools to use it for identification.

Link: https://lore.kernel.org/r/20210110224850.1880240-21-suzuki.poulose@arm.com
Cc: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20210201181351.1475223-23-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>