OMAPDSS: HDMI: OMAP4: Remove invalid I2S settings

According to the most up-to-date documentation from Texas Instruments,
the configuration of High Bitrate Audio is not possible. Also, it is
not possible to set polarity of the I2S Word Select signal. This patch
removes the invalid settings.

Signed-off-by: Ricardo Neri <ricardo.neri@ti.com>