documentation/bsp-guide/bsp.xml: Added reference to Kernel documentation.
I added a reference to the specific section in the kernel documentation
that describes how to create a BSP Based on an existing similar
BSP. The tools we have that create the PDF manuals from the DocBook
XML do not support cross-referencing to another PDF manual. So, I was
left with adding a clunky text-based reference to the section and a link
to the docs page on the web-site.
Signed-off-by: Scott Rifenbark <scott.m.rifenbark@intel.com>
