drm/sun4i: dw-hdmi: Fix missing put_device() call in sun8i_hdmi_phy_get

The reference taken by 'of_find_device_by_node()' must be released when
not needed anymore.
Add the corresponding 'put_device()' in the error handling path.

Fixes: 9bf37977

 ("drm/sun4i: dw-hdmi: Make HDMI PHY into a platform device")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20220107083633.20843-1-linmq006@gmail.com