drm/amd/display: fix initial bounding box values for dcn3.02

[Why]
Initial bounding box values are updated in dcn30_update_bw_bounding_box
 but they use dcn3_0_soc and dcn3_0_ip instead of dcn3_02_soc and
 dcn3_02_ip

[How]
Add dcn302_update_bw_bounding_box and
 dcn302_get_optimal_dcfclk_fclk_for_uclk so it uses
 dcn3_02_soc and dcn3_02_ip.
Use sr_exit_time_us, sr_enter_plus_exit_time_us,
 from dcn30 on dcn302 to fix flicker on eDP.
 Also use dram_clock_change_latency_us from dcn30.

Signed-off-by: Samson Tam <Samson.Tam@amd.com>
Reviewed-by: Joshua Aberback <Joshua.Aberback@amd.com>
Acked-by: Anson Jacob <Anson.Jacob@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>