* Replace creating an empty PYTHON3_PKG_DIR with setting filespec to an
  empty value

* Disable the default Python package build recipe (with
  PYTHON3_PKG_BUILD:=0) and set an empty Build/Compile

* Remove VARIANT:=python3 and PROVIDES (providing the same name as the
  package)

* Add PKG_BUILD_PARALLEL:=1

Signed-off-by: Jeffery To <jeffery.to@gmail.com>