drm/amd/display: Fix nanosec stat overflow

[Why]
Nanosec stats can overflow on long running systems potentially causing
statistic logging issues.

[How]
Use 64bit types for nanosec stats to ensure no overflow.

Reviewed-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Aric Cyr <aric.cyr@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/amd/display: Clean up code warnings

- Fix constness of string parameters
- Fix zero-initialization of structs which cannot take a 0 literal as the
first field, for example enums

Reviewed-by: Dillon Varone <dillon.varone@amd.com>
Acked-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Aric Cyr <aric.cyr@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/amd/display: Handle persistence in DM

[Why]
Remove dm_write_persistent_data and dm_read_persistent_data as
persistence should be handled in DM.

[How]
Remove functions. Move read/write calls into DM layer while maintaining
logic.

Signed-off-by: Jaehyun Chung <jaehyun.chung@amd.com>
Reviewed-by: Anthony Koo <Anthony.Koo@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/amd/display: Add fullscreen transitions to log

Signed-off-by: Anthony Koo <Anthony.Koo@amd.com>
Reviewed-by: Aric Cyr <Aric.Cyr@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Acked-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/amd/display: Implement stats logging

Stats will be used for debug purposes

Signed-off-by: Anthony Koo <Anthony.Koo@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Acked-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>