drm/crtc-helper: use drm_framebuffer flags

The "flags" parameter of the DRM_IOCTL_MODE_ADDFB2 ioctl must be
propagated and used by the driver.
The only possible value of flags is DRM_MODE_FB_INTERLACED.
Signed-off-by: Fabien Dessenne <fabien.dessenne@st.com>
Reviewed-by: Benjamin GAIGNARD <benjamin.gaignard@st.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/drm_crtc_helper.c

@@ -818,6 +818,7 @@ void drm_helper_mode_fill_fb_struct(struct drm_framebuffer *fb,
 	drm_fb_get_bpp_depth(mode_cmd->pixel_format, &fb->depth,
 				    &fb->bits_per_pixel);
 	fb->pixel_format = mode_cmd->pixel_format;
+	fb->flags = mode_cmd->flags;
 }
 EXPORT_SYMBOL(drm_helper_mode_fill_fb_struct);