ep93xx_Eth: Updated DMA allocations

Dragging in mainline changes
ep93xx_eth: Use newer pr_XXX print functions

Pulled from mainline
ep93xx_eth: Updated buffer allocation

Pulled from mainline
ep93xx_eth: Don't warn about skb allocation failures

These simply result in dropped packets, and don't require a full stack dump
ep93xx_eth: Minr irqsave change
yaffs2: Import the latest version of yaffs

This corresponds to commit 53892fe9e3770882fd8f53f1a8a392d875175b4b
There have been some improvements in YAFFS since 2009, when we last imported.
In particular we now get much better mount time due to block summaries,
and a slight read performance improvement (~5%)