boards/qemumicroblaze: Added ramdisk boot args to device tree

The MicroBlaze kernel uses device tree boot args before it attempts to
use the arguments provided by the bootloader (e,g, u-boot/qemu).

This change expects that the qemumicroblaze machine is always loaded
with a initrd.

Signed-off-by: Nathan Rossi <nathan.rossi@xilinx.com>
qemu: Enabled required patches

* Verified existing patches against 1.6.1
* Re-enabled required patches for MicroBlaze and Zynq

Signed-off-by: Nathan Rossi <nathan.rossi@xilinx.com>
qemu: Add patch to resolve MicroBlaze ethernet issues

* Add patch to resolve the QEMU segfault when a AXI Ethernet device
  attempts to transmit/recieve packets.
* Patch is from mailing list, back-ported for 1.6.1.

Signed-off-by: Nathan Rossi <nathan.rossi@xilinx.com>