gnome-control-center: add libgtop dependency

* it fails without it:
  | make[3]: *** [libcommon.la] Error 1
  | make[3]: Leaving directory `work/armv5te-oe-linux-gnueabi/gnome-control-center/2.32.1-r1/gnome-control-center-2.32.1/capplets/common'

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>