- Add ioctl method to enable allocating the apb buffer.
- Add RX methods to set data width, sample rate, channels and
for receiving data from the I2S peripheral.
- Update the i2schar defconfig to enable the I2S receiver.
- Add nxlooper defconfig to enable testing the RX interface.
- Add specific bindings on ESP32 bringup to enable nxlooper
to work without the need of any specific codec.