drm/vc4: hdmi: Pass vc4_hdmi to vc4_hdmi_supports_scrambling()

Simplify vc4_hdmi_supports_scrambling() by changing its first parameter
from struct drm_encoder to struct vc4_hdmi.

Signed-off-by: José Expósito <jose.exposito89@gmail.com>
Link: https://lore.kernel.org/r/20221110134752.238820-2-jose.exposito89@gmail.com


Signed-off-by: Maxime Ripard <maxime@cerno.tech>