drm/amd/display: Stop amdgpu_dm initialize when stream nums greater than 6

[Why]
Coverity reports OVERRUN warning. Should abort amdgpu_dm
initialize.

[How]
Return failure to amdgpu_dm_init.
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Acked-by: Tom Chung <chiahsuan.chung@amd.com>
Signed-off-by: Hersen Wu <hersenxs.wu@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

@@ -4566,7 +4566,10 @@ static int amdgpu_dm_initialize_drm_device(struct amdgpu_device *adev)
 
 	/* There is one primary plane per CRTC */
 	primary_planes = dm->dc->caps.max_streams;
-	ASSERT(primary_planes <= AMDGPU_MAX_PLANES);
+	if (primary_planes > AMDGPU_MAX_PLANES) {
+		DRM_ERROR("DM: Plane nums out of 6 planes\n");
+		return -EINVAL;
+	}
 
 	/*
 	 * Initialize primary planes, implicit planes for legacy IOCTLS.