drm/msm/hdmi: fix indent

Remove the excess leading tabs.
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/d06f990311ba0108357512c46b3e8328bacedcd0.1706038510.git.jani.nikula@intel.com