drivers/net/dwc_gmac: Use uncached memory for DMA descriptors
drivers/net/dwc_gmac: Use uncached memory for DMA descriptors

In certain circumstances dcache ops for DMA descriptor were causing
unintentional data invalidation.

Dynamic non-cached memory allocation is used to fix this issue

embox/embox,embox/embox,embox/embox,embox/embox,embox/embox,embox/embox