rt5645: Split out the machine driver for the Edge TPU dev boards

This splits out the machine driver from the fsl-asoc-card machine driver in an
attempt to resolve user-space issues with the hwparams and clocking issues
between pulseaudio and the driver.

Change-Id: Ia0eef7ef7d08ab466e5460ccbf4f48b77d85d81c
6 files changed