bitbake: bitbake-user-manual/bitbake-user-manual: remove YP as build system

YP is not a build system, so it can not be used as build system example.

(Bitbake rev: dc86d38816aeb0fcbceb34cbaaa6ed98d33383e9)

Signed-off-by: Leonardo Sandoval <leonardo.sandoval.gonzalez@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/doc/bitbake-user-manual/bitbake-user-manual-intro.xml

@@ -440,7 +440,7 @@
                     Build Checkout:</emphasis>
                     A final possibility for getting a copy of BitBake is that it
                     already comes with your checkout of a larger Bitbake-based build
-                    system, such as Poky or Yocto Project.
+                    system, such as Poky.
                     Rather than manually checking out individual layers and
                     gluing them together yourself, you can check
                     out an entire build system.