dmaengine: add BCM2708 DMA support

This driver provides only DMA_CYCLIC mode.

Signed-off-by: Florian Meier <koalo@koalo.de>
ASoC: Add I2S driver for BCM2708

This driver handles audio input and output for the I2S interface
of the BCM2708 that is used by the Raspberry Pi.

Signed-off-by: Florian Meier <koalo@koalo.de>