arm: tegra: Change DDC freq to 10KHz

Bug 949759

Reduce DDC freq. The original freq is 100KHz, but some edid communication
at this rate on some monitors like acer H243HX may fail

Change-Id: Ib087025a35ff085b4bf618b70100fe6670c3eaec
Signed-off-by: Hao Tang <htang@nvidia.com>
Reviewed-on: http://git-master/r/88261
Reviewed-by: Simone Willett <swillett@nvidia.com>
Tested-by: Simone Willett <swillett@nvidia.com>
board-x3-audio: Set default I2S channels to 2 and some cleanup.

Change-Id: I26b39d7a1ee0175c8399b20edca95c07bd7333bd