MLK-17289-5: hdmi cec: change cec driver architecture

MLK-17289-5: hdmi cec: change cec driver architecture

Change hdmi cec driver architecture.
Embedded cec function to hdmi driver.
Rewrite cec_read and cec_write fucntion
to support both imx8qm and imx8mq cec.

Signed-off-by: Sandor Yu <Sandor.yu@nxp.com>
Also include MLK-17289-6: hdp drm: Add cec register/unregister function

Add cec register/unregister function in hdp drm driver.
Add is_cec variable to check cec function setting in dtb.

Squashed MLK-17289-5 and MLK-17289-6 from imx_4.9.y because they only
build together.

Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>