drm/amd/display: decouple global lock out of pipe control lock

[why]
hwss should not guess what type of pipe lock is needed.
The caller of the lock function should know
the right type of pipe lock.
Decouple the setup of global lock outside of pipe control lock
logic.

Signed-off-by: Wenjing Liu <Wenjing.Liu@amd.com>
Reviewed-by: Anthony Koo <Anthony.Koo@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>