ASoC: fsl: create fsl_utils to accommodate the common functions

There is some amount of code duplication between mpc8610_hpcd and
p1022_ds machine drivers, and the same code will be duplicated again
when another new machine driver is added.  The patch creates fsl_utils
to accommodate the common functions to stop the code duplication.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Timur Tabi <timur@freescale.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>