Qemu changes pid when starting up. On a loaded machine, this can result
in the incorrect pid being returned. Since qemu will take a few seconds to
boot anyway, we might as well delay a short while and allow things to settle
which should fix various race issues being seen on the autobuilder.
(From OE-Core rev: 27d00d62281a822efbbc189a3bab1d9b25fba3a7)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>