coresight: Add claim tag warnings and debug messages

coresight: Add claim tag warnings and debug messages

Add a dev_dbg() message so that external debugger conflicts are more
visible. There are multiple reasons for -EBUSY so a message for this
particular one could be helpful. Add errors for and enumerate all the
other cases that are impossible.

Reviewed-by: Leo Yan <leo.yan@arm.com>
Reviewed-by: Yeoreum Yun <yeoreum.yun@arm.com>
Signed-off-by: James Clark <james.clark@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20250325-james-coresight-claim-tags-v4-3-dfbd3822b2e5@linaro.org