drm/amd/display: Remove unused struct freesync_context

All references to struct freesync_context were removed, so remove the
struct freesync_context itself and its entry on struct dc_stream_state.

Reviewed-by: Rodrigo Siqueira <[e-mail]>
Signed-off-by: Maíra Canal <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

drivers/gpu/drm/amd/display/dc/dc_stream.h

···
 	bool is_abm_supported;
 };
 
-// TODO: References to this needs to be removed..
-struct freesync_context {
-	bool dummy;
-};
-
 enum hubp_dmdata_mode {
 	DMDATA_SW_MODE,
 	DMDATA_HW_MODE
···
 	uint8_t dsc_packed_pps[128];
 	struct rect src; /* composition area */
 	struct rect dst; /* stream addressable area */
-
-	// TODO: References to this needs to be removed..
-	struct freesync_context freesync_ctx;
 
 	struct audio_info audio_info;