drm/vc4: hdmi: Put the device on error in pre_crtc_configure

In the vc4_hdmi_encoder_pre_crtc_configure() function error path we
never actually call pm_runtime_put() even though
pm_runtime_resume_and_get() is our very first call.

Fixes: 4f6e3d66 ("drm/vc4: Add runtime PM support to the HDMI encoder driver")
Signed-off-by: Maxime Ripard <maxime@cerno.tech>