drm/tilcdc: include linux/pinctrl/consumer.h again

This was apparently dropped by accident in a recent
cleanup, causing a build failure in some configurations now:

drivers/gpu/drm/tilcdc/tilcdc_tfp410.c:296:12: error: implicit declaration of function 'devm_pinctrl_get_select_default' [-Werror,-Wimplicit-function-declaration]

Fixes: fcb57664

 ("drm/tilcdc: drop use of drmP.h")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Jyri Sarha <jsarha@ti.com>
Link: https://patchwork.freedesktop.org/patch/msgid/02b03f74cf941f52a941a36bdc8dabb4a69fd87e.1569852588.git.jsarha@ti.com
Acked-by: Sam Ravnborg <sam@ravnborg.org>