The following changes add processing to initialize the Xilinx 16550 UART
in the boot wrapper for Virtex targets without firmware.  Normally the
boot wrapper assumes that the serial port has already been initialized by
firmware.

The wrapper was also modified to add the 440 build.
Signed-off-by: NJohn Linn <john.linn@xilinx.com>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

This target produces a flat binary rather than an ELF file,
fixes the entry point at the beginning of the image, and takes
a complete device tree with no fixups needed.
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>
Signed-off-by: NJosh Boyer <jwboyer@linux.vnet.ibm.com>