drm/amd/display: Disable display writeback on Linux for NV10

[WHY] system crash when initialize dwb
current linux driver does not support dwb.
 disable this feature for now.

[HOW] set num_dwb = 0 to disable dwb for now
Signed-off-by: hersen wu <hersenxs.wu@amd.com>
Reviewed-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c

@@ -623,7 +623,7 @@ static const struct resource_caps res_cap_nv10 = {
 		.num_audio = 7,
 		.num_stream_encoder = 6,
 		.num_pll = 6,
-		.num_dwb = 1,
+		.num_dwb = 0,
 		.num_ddc = 6,
 		.num_vmid = 16,
 #ifdef CONFIG_DRM_AMD_DC_DSC_SUPPORT