coresight: Remove .cpu_id() callback from source ops

coresight: Remove .cpu_id() callback from source ops

The CPU ID can be fetched directly from the coresight_device structure,
so the .cpu_id() callback is no longer needed.

Remove the .cpu_id() callback from source ops and update callers
accordingly.

Tested-by: Jie Gan <jie.gan@oss.qualcomm.com>
Reviewed-by: Yeoreum Yun <yeoreum.yun@arm.com>
Reviewed-by: James Clark <james.clark@linaro.org>
Tested-by: James Clark <james.clark@linaro.org>
Signed-off-by: Leo Yan <leo.yan@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20260515-arm_coresight_path_power_management_improvement-v14-5-f88c4a3ecfe9@arm.com