packagegroup-webos-test: Don't include valgrind for armv[456]*

* qemuarm webos-image-devel builds are failing, because
  valgrind does not support armv5te

Open-webOS-DCO-1.0-Signed-off-by: Martin Jansa <martin.jansa@lge.com>
Change-Id: Icb9b89e33f5404b6228085419dc0492f2b611637
Reviewed-on: https://g2g.palm.com/2082
Reviewed-by: Build Verification
Reviewed-by: Martin Jansa <Martin.Jansa@lge.com>
Tested-by: Martin Jansa <Martin.Jansa@lge.com>
Reviewed-by: Susan Montooth <susan.montooth@lge.com>
Reviewed-by: Herb Kuta <herb.kuta@lge.com>