ASoC: add support for the Freescale / iVeia P1022 RDK reference board

This small reference boards has a Freescale P1022 dual-core PowerPC SOC
and a Wolfson Microelectronics WM8960 codec.

Signed-off-by: Timur Tabi <timur@freescale.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>