drm/amd/display: Fix idle optimizations entry log

[Why & How]
Whether we really enter idle optimizations are decided within DC.
Printing into dmesg before calling the DC API gives an incorrect
indication that we are entering idle optimization in cases where its
disabled manually.

To fix this, remove the print in DM and add them in DC

Reviewed-by: Alvin Lee <alvin.lee2@amd.com>
Signed-off-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Tom Chung <chiahsuan.chung@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>