drm/amd/display: Change HDCP update sequence for DM

Refactor the sequence in hdcp_update_display() to use
mod_hdcp_update_display().

Previous sequence:
	- remove()->add()

This Sequence was used to update the display, (mod_hdcp_update_display
didn't exist at the time). This meant for any hdcp updates (type changes,
enable/disable) we would remove, reconstruct, and add. This leads to
unnecessary calls to psp eventually

New Sequence using mod_hdcp_update_display():
	- add() once when stream is enabled
	- use update() for all updates

The update function checks for prev == new states and will not
unnecessarily end up calling psp via add/remove.

Reviewed-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Acked-by: Tom Chung <chiahsuan.chung@amd.com>
Signed-off-by: Bhawanpreet Lakha <bhawanpreet.lakha@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>