Enable Analog Devices ADV7842 CEC support

configname: CONFIG_VIDEO_ADV7842_CEC

Linux Kernel Configuration
└─>Device Drivers
└─>Multimedia support
└─>Media ancillary drivers
└─>Video decoders
└─>Enable Analog Devices ADV7842 CEC support
In linux kernel since version 3.10 (release Date: 2013-06-30)  
When selected the adv7842 will support the optional
HDMI CEC feature.

selects
CONFIG_CEC_CORE