drm/amd/display: Fix comparison error in dcn21 DML

[why]
A comparison error made it possible to not iterate through all the
specified prefetch modes.

[how]
Correct "<" to "<="
Reviewed-by: Dmytro Laktyushkin <Dmytro.Laktyushkin@amd.com>
Reviewed-by: Yongqiang Sun <Yongqiang.Sun@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Victor Lu <victorchengchi.lu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dml/dcn21/display_mode_vba_21.c

@@ -4889,7 +4889,7 @@ void dml21_ModeSupportAndSystemConfigurationFull(struct display_mode_lib *mode_l
 				}
 			} while ((locals->PrefetchSupported[i][j] != true || locals->VRatioInPrefetchSupported[i][j] != true)
 					&& (mode_lib->vba.NextMaxVStartup != mode_lib->vba.MaxMaxVStartup[0][0]
-						|| mode_lib->vba.NextPrefetchMode < mode_lib->vba.MaxPrefetchMode));
+						|| mode_lib->vba.NextPrefetchMode <= mode_lib->vba.MaxPrefetchMode));
 
 			if (locals->PrefetchSupported[i][j] == true && locals->VRatioInPrefetchSupported[i][j] == true) {
 				mode_lib->vba.BandwidthAvailableForImmediateFlip = locals->ReturnBWPerState[i][0];