The patch that moved the dcss node from fsl-imx8mq-evk.dts to
fsl-imx8mq.dtsi reverted Sandor's patch 8c9aa9e which removed the APB
clock from assigned-clocks, this way breaking the HDMI CEC
functionality.
This patch re-applies the changes made initially in 8c9aa9e.
Signed-off-by: Robert Chiras <robert.chiras@nxp.com>