coresight: Convert tag clear function to take a struct csdev_access

The self hosted claim tag will be reset on device probe in a later
commit. We'll want to do this before coresight_register() is called so
won't have a coresight_device and have to use csdev_access instead.

Also make them public and create locked and unlocked versions for
later use.

These look functions look like they set the whole tags register as one
value, but they only set and clear the self hosted bit using a SET/CLR
bits mechanism so also rename the functions to reflect this better.

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-v4-1-dfbd3822b2e5@linaro.org