ARM: dts: k2g-evm: Enable audio support

Analog and HDMI audio is sharing the same McASP2 pins on the EVM, but when
the LCD is used then the HDMI is disabled, so we remove the HDMI audio
link in the lcd DTS file.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Jyri Sarha <jsarha@ti.com>