drm/amd/display: Disable scaling on DCE6 for now

[ Upstream commit 0e190a0 ]

Scaling doesn't work on DCE6 at the moment, the current
register programming produces incorrect output when using
fractional scaling (between 100-200%) on resolutions higher
than 1080p.

Disable it until we figure out how to program it properly.

Fixes: 7c15fd8 ("drm/amd/display: dc/dce: add initial DCE6 support (v10)")
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Timur Kristóf <timur.kristof@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: Timur Kristóf

drivers/gpu/drm/amd/display/dc/dce60/dce60_resource.c

@@ -403,13 +403,13 @@ static const struct dc_plane_cap plane_cap = {
 	},
 
 	.max_upscale_factor = {
-			.argb8888 = 16000,
+			.argb8888 = 1,
 			.nv12 = 1,
 			.fp16 = 1
 	},
 
 	.max_downscale_factor = {
-			.argb8888 = 250,
+			.argb8888 = 1,
 			.nv12 = 1,
 			.fp16 = 1
 	}