drm/amdgpu/display/dce11: only enable FBC when selected

Causes a black screen on a Stoney laptop.

Bug: https://bugs.freedesktop.org/show_bug.cgi?id=108577Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dce110/dce110_resource.c

@@ -1362,6 +1362,7 @@ static bool construct(
 		pool->base.sw_i2cs[i] = NULL;
 	}
 
+	if (dc->config.fbc_support)
 		dc->fbc_compressor = dce110_compressor_create(ctx);
 
 	if (!underlay_create(ctx, &pool->base))