OMAPDSS: hdmi: Remove __exit qualifier from hdmi_uninit_output()

Remove __exit qualifier from hdmi_uninit_output() because it is used
also in omapdss_hdmihw_probe().

Signed-off-by: Jyri Sarha <jsarha@ti.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>