drm/amd/display: Change min_h_sync_width from 8 to 4

[Why]
Some display's hsync width is lower than the minimum dcn20 is set
to support right now. This will cause optc1_validate_timing to fail which
eventually will result in wrong set mode. This was set to 8 as per
HW team's request for no valid reason.

[How]
Changing min_h_sync_width to 4 will let us validate timing for
preffered mode and light up the headset. This change was made
to Vega 10 before for a similar issue.
Signed-off-by: Fatemeh Darbehani <fatemeh.darbehani@amd.com>
Reviewed-by: Joshua Aberback <Joshua.Aberback@amd.com>
Acked-by: Aric Cyr <Aric.Cyr@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dcn20/dcn20_optc.c

@@ -535,7 +535,7 @@ void dcn20_timing_generator_init(struct optc *optc1)
 	optc1->min_h_blank = 32;
 	optc1->min_v_blank = 3;
 	optc1->min_v_blank_interlace = 5;
-	optc1->min_h_sync_width = 8;
+	optc1->min_h_sync_width = 4;//	Minimum HSYNC = 8 pixels asked By HW in the first place for no actual reason. Oculus Rift S will not light up with 8 as it's hsyncWidth is 6. Changing it to 4 to fix that issue.
 	optc1->min_v_sync_width = 1;
 	optc1->comb_opp_id = 0xf;
 }