It was observed on a mx31pdk board that audio playback only worked when the bootloader was Redboot, and
did not work when U-boot was used.

Comparing the sources of these bootloaders showed that the AIPS registers were not setup in U-boot.

Instead of relying on the bootloader to setup the AIPS registers, do it in the kernel so that audio
playback can work independantly of the bootloader being used.

Copied the AIPS settings from Redboot to the kernel.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>