staging: video: imx: Select VIDEOMODE_HELPERS for parallel display

staging: video: imx: Select VIDEOMODE_HELPERS for parallel display

Without this, I get the following problem when building kernel:

drivers/built-in.o: In function `imx_pd_connector_get_modes':
/linux-2.6/drivers/staging/imx-drm/parallel-display.c:78: undefined reference to `of_get_drm_display_mode'
make: *** [vmlinux] Error 1

Signed-off-by: Marek Vasut <[email protected]>
Cc: Sascha Hauer <[email protected]>
Cc: Philipp Zabel <[email protected]>
Cc: Fabio Estevam <[email protected]>
Acked-by: Sascha Hauer <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>