drm/ipv3: add CONFIG_OF dependency for DRM_OF_DISPLAY_MODE_BRIDGE

drm/ipv3: add CONFIG_OF dependency for DRM_OF_DISPLAY_MODE_BRIDGE

Without this, not all dependencies are met here.

  Depends on [n]: HAS_IOMEM [=y] && DRM [=y] && DRM_BRIDGE [=y] && OF [=n]
  Selected by [y]:
  - DRM_IMX_PARALLEL_DISPLAY [=y] && HAS_IOMEM [=y] && DRM [=y] && DRM_IMX [=y]
  - DRM_IMX_LDB [=y] && HAS_IOMEM [=y] && DRM [=y] && DRM_IMX [=y] && COMMON_CLK [=y]

Fixes: ba2db93cf3d5 ("drm/bridge: Move legacy bridge driver out of imx directory for multi-platform use")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Reviewed-by: Damon Ding <damon.ding@rock-chips.com>
Link: https://patch.msgid.link/20260429140024.192432-1-arnd@kernel.org
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>