Some boards don't have such a regulator, and don't need one to enable
HDMI display. Make it optional, fixing hdmi display for those boards.
Also surround the regulator code with a config check on DM_REGULATOR.
Reported-by: Mohammad Rasim <mohammad.rasim96@gmail.com>
Signed-off-by: Maxime Jourdan <mjourdan@baylibre.com>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Tested-by: Mohammad Rasim <mohammad.rasim96@gmail.com>
f944b15966