.gitignore: Drop stale entries

(From OE-Core rev: 832240f2c5b4f4af8a8e5b652c7e234560104cc4)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

.gitignore

@@ -14,24 +14,9 @@ meta-maemo
 meta-extras
 meta-m2
 meta-prvt*
-poky-autobuilder*
 *.swp
 *.orig
 *.rej
 *~
-documentation/poky-ref-manual/poky-ref-manual.html
-documentation/poky-ref-manual/poky-ref-manual.pdf
-documentation/poky-ref-manual/poky-ref-manual.tgz
-documentation/poky-ref-manual/bsp-guide.html
-documentation/poky-ref-manual/bsp-guide.pdf
-documentation/bsp-guide/bsp-guide.html
-documentation/bsp-guide/bsp-guide.pdf
-documentation/bsp-guide/bsp-guide.tgz
-documentation/yocto-project-qs/yocto-project-qs.html
-documentation/yocto-project-qs/yocto-project-qs.tgz
-documentation/kernel-manual/kernel-manual.html
-documentation/kernel-manual/kernel-manual.tgz
-documentation/kernel-manual/kernel-manual.pdf
-