docs: fix generation of docs from VPATH build
docs: fix generation of docs from VPATH build

When generating docs in a VPATH build we get a failure to
create a file due to the 'internals' subdir not existing:

  Generating internals/locking.html.tmp
  /bin/sh: line 3: internals/locking.html.tmp: No such file or directory
  rm: cannot remove ‘internals/locking.html.tmp’: No such file or directory
  Makefile:2229: recipe for target 'internals/locking.html.tmp' failed
  make: *** [internals/locking.html.tmp] Error 1

For some reason, make has decided to run the target

  %.html.tmp: %.html.in site.xsl page.xsl sitemap.html.in $(acl_generated)

instead of the target

  internals/%.html.tmp: internals/%.html.in subsite.xsl page.xsl sitemap.html.in

Removing '$(acl_generated)' from the first target, inexplicably
causes make to now run the correct target for the internals/
files.

Rather than figure this out, lets just combine the two targets
into one.

Signed-off-by: Daniel P. Berrange <bb938cf255e055ff3507f2627d214e8e62118fcf@redhat.com>

zippy2/libvirt,jardasgit/libvirt,taget/libvirt,crobinso/libvirt,datto/libvirt,rlaager/libvirt,fabianfreyer/libvirt,rlaager/libvirt,jfehlig/libvirt,eskultety/libvirt,rlaager/libvirt,eskultety/libvirt,andreabolognani/libvirt,eskultety/libvirt,fabianfreyer/libvirt,jfehlig/libvirt,olafhering/libvirt,jardasgit/libvirt,andreabolognani/libvirt,VenkatDatta/libvirt,jardasgit/libvirt,taget/libvirt,libvirt/libvirt,zippy2/libvirt,VenkatDatta/libvirt,nertpinx/libvirt,libvirt/libvirt,rlaager/libvirt,andreabolognani/libvirt,jardasgit/libvirt,crobinso/libvirt,nertpinx/libvirt,jfehlig/libvirt,fabianfreyer/libvirt,zippy2/libvirt,nertpinx/libvirt,crobinso/libvirt,olafhering/libvirt,VenkatDatta/libvirt,crobinso/libvirt,eskultety/libvirt,datto/libvirt,taget/libvirt,libvirt/libvirt,olafhering/libvirt,datto/libvirt,taget/libvirt,jfehlig/libvirt,VenkatDatta/libvirt,datto/libvirt,olafhering/libvirt,nertpinx/libvirt,rlaager/libvirt,eskultety/libvirt,zippy2/libvirt,nertpinx/libvirt,andreabolognani/libvirt,taget/libvirt,jardasgit/libvirt,fabianfreyer/libvirt,fabianfreyer/libvirt,datto/libvirt,libvirt/libvirt,VenkatDatta/libvirt,andreabolognani/libvirt