recipes: Drop remaining PR values from recipes

* as oe-core did in:
  https://git.openembedded.org/openembedded-core/commit/?id=d4c346e8ab

* when people are have to maintain own PRs for recipes in oe-core, they
  might add them for meta-oe recipes at the same time when upgrading
  to next LTS

Signed-off-by: Martin Jansa <martin.jansa@gmail.com>
Signed-off-by: Khem Raj <raj.khem@gmail.com>

meta-xfce/recipes-xfce/packagegroups/packagegroup-xfce-base.bb

@@ -1,6 +1,5 @@
 SUMMARY = "All packages required for a base installation of XFCE"
 SECTION = "x11/wm"
-PR = "r5"
 
 # librsvg-gtk gets debian renamed to librsvg-2-gtk
 PACKAGE_ARCH = "${TUNE_PKGARCH}"

meta-xfce/recipes-xfce/packagegroups/packagegroup-xfce-extended.bb

@@ -1,7 +1,6 @@
 SUMMARY = "All packages for full XFCE installation"
 SECTION = "x11/wm"
 
-PR = "r10"
 
 inherit packagegroup features_check