drm/sun4i: hdmi: Fix another error handling path in 'sun4i_hdmi_bind()'

If we can not get the HDMI DDC clock, we still need to free some
resources before returning.

Fixes: 939d749a ("drm/sun4i: hdmi: Add support for controller hardware variants")
Reviewed-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/5e0084af4ad57e9eea3bca5bd8e2e95970cd6714.1521413031.git.christophe.jaillet@wanadoo.fr