[meta-xilinx] adding patch file for u-boot

[Richard Cagley]

i need to add a patch file for u-boot for a custom machine.

In meta-xilinx master branch u-boot-spl-xlnx_2015.01.bb includes
u-boot-xlnx-2015.01.inc, which includes other patches, such as for the
picozed.

If I just try to make a u-boot-spl-xlnx_2015.01.bbappend file bitbake fails

ERROR: Nothing PROVIDES 'virtual/zynq7-platform-init' (but
/opt/oe/master/meta-xilinx/recipes-bsp/u-boot/u-boot-spl-xlnx_2015.01.bb
DEPENDS on or otherwise requires it)

I guess I need to append the include file with my own patch. But, I
can't figure out how to append an include file or I guess
alternatively pre-prepend the .bb file.

Does anyone have a recommendation for adding custom machines/patches
to u-boot with meta-xilinx?