Use the TraceID API to allocate ETM trace IDs dynamically.

As with the etm4x we allocate on enable / disable for perf,
allocate on enable / reset for sysfs.

Additionally we allocate on sysfs file read as both perf and sysfs
can read the ID before enabling the hardware.

Remove sysfs option to write trace ID - which is inconsistent with
both the dynamic allocation method and the fixed allocation method
previously used.
Signed-off-by: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230116124928.5440-7-mike.leach@linaro.org