coresight: Simplify sysfs accessors by using csdev_access abstraction

The coresight_device struct is available in the sysfs accessor, and this
contains a csdev_access struct which can be used to access registers.
Use this instead of passing in the type of each drvdata so that a common
function can be shared between all the cs drivers.

No functional changes.

Signed-off-by: James Clark <james.clark@arm.com>
Reviewed-by: Mike Leach <mike.leach@linaro.org>
Link: https://lore.kernel.org/r/20220830172614.340962-3-james.clark@arm.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>