linux-wandboard

MLK-16197-9 video: fbdev: dcss: improve dtg config logic

Do the following improvements about DTG config:

    1. move db and sb loading position config from
       'dcss_dtg_config' to 'dcss_dtg_start'.
    2. Only one DTG trigger config is required which
       is put in 'dcss_dtg_start'.
    3. move 'dcss_dtg_config' call from 'dcss_blank'
       to 'dcss_set_par'.
    4. add default background color configs for both
       graph and video layers in 'dcss_dtg_start'.
    5. remove channel enable and disable function in
       'dcss_channel_blank'.

All the above improvements focus on making dtg config
logic more simple and more clear.

Signed-off-by: Fancy Fang <chen.fang@nxp.com>