drm/msm/hdmi: Fix missing put_device() call in msm_hdmi_get_phy

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: e00012b2

 ("drm/msm/hdmi: Make HDMI core get its PHY")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20220107085026.23831-1-linmq006@gmail.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>