ARM: at91: sama5d3xek: reserve dma channel for audio
ARM: at91: sama5d3xek: reserve dma channel for audio

We set the DMA configuration on USARTs in the SoC DT in (ARM: at91: sama5d3:
add usart dma configurations). As the audio must work with DMA channels, we
reserve some dma channels for audio, or else audio won't work.

Signed-off-by: Bo Shen <b3e6a3251704a94eee1cf08e0adc382e6cb535ee@atmel.com>
[45b517be0e5ec6dc3a39715767c1d18e090d39b4@atmel.com: move to the sama5d3xmb.dtsi to cover all board variants]
Signed-off-by: Nicolas Ferre <45b517be0e5ec6dc3a39715767c1d18e090d39b4@atmel.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs