ARM: dts: keystone-k2g-evm: add HDMI and analog audio data

The board is using McASP2 for both analog (tlv320aic3106) and
HDMI (SiI9022) audio.
12.288MHz oscillator provides the MCLK for both aic3106 and SiI9022.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>