coresight: Refactor sysfs connection group cleanup

coresight: Refactor sysfs connection group cleanup

Move the sysfs connection group cleanup into coresight_remove_conns(),
so that the driver removes connections and related sysfs resources in
one go.

As side effect, the csdev argument to coresight_release_platform_data()
is no longer needed; adjust the code for this.

Reviewed-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/20260209-arm_coresight_refactor_dev_register-v4-5-62d6042f76f7@arm.com