Revert "recipes: Replace PR_append with EXTENDPRAUTO_append"

This reverts commit 92bb7ab19ecc5e0b9eddb85311aedc146c9de561.
This slipped in before everything else was ready. Sorry for any
inconvenience.

Open-webOS-DCO-1.0-Signed-off-by: Herb Kuta <herb.kuta@lge.com>
Change-Id: Ifd7188ba71d5b4920e813b74c8b2cde11caf963b
Reviewed-on: https://g2g.palm.com/3161
Reviewed-by: Build Verification
Reviewed-by: Susan Montooth <susan.montooth@lge.com>
Tested-by: Susan Montooth <susan.montooth@lge.com>