drm/amd/display: Update phantom pipe enable / disable sequence

Previously we would call apply_ctx_to_hw to enable and disable
phantom pipes. However, apply_ctx_to_hw can potentially update
non-phantom pipes as well which is undesired. Instead of calling
apply_ctx_to_hw as a whole, call the relevant helpers for each
phantom pipe when enabling / disabling which will avoid us modifying
hardware state for non-phantom pipes unknowingly.

The use case is for an FRL display where FRL_Update is requested
by the display. In this case link_state_valid flag is cleared in
a passive callback thread and should be handled in the next stream /
link update. However, due to the call to apply_ctx_to_hw for the
phantom pipes during a flip, the main pipes were modified outside
of the desired sequence (driver does not handle link_state_valid = 0
on flips).

Cc: stable@vger.kernel.org # 6.6+
Reviewed-by: Samson Tam <samson.tam@amd.com>
Acked-by: Hamza Mahfooz <hamza.mahfooz@amd.com>
Signed-off-by: Alvin Lee <alvin.lee2@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>