MIPS: JZ4750D: Add a380-audio device defs to board-a380.c
inird: Remove previous initrd
initrd: Use text device tree description instead of initrd.cpio binary

  - Get mininit from http://code.google.com/p/dingoo-linux/
  - Make a list of dirs and nods in initrd/tree.txt
  - Let kernel create initrd.cpio for us