Drop PRIORITY variable

As discussed on the mailing list, this variable isn't useful and if wanted
would be better implemented by distros using pn-X overrides.

This patch executes:

find . -regex ".*\.\(bb\|inc\)$" | xargs sed -i '/^PRIORITY = ".*"$/d'

against the tree removing the references. Thanks to Phil Blundell for
the command.

(Prompted by oe-core rev: d122343362669c683acc4af295971a62cbc823fc)

Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>

meta-gpe/recipes-graphics/gpe-scap/gpe-scap_1.4.bb

@@ -1,6 +1,5 @@
 DESCRIPTION = "A GPE application that allows you to take screenshots."
 SECTION = "gpe"
-PRIORITY = "optional"
 
 LICENSE = "GPLv2"
 LIC_FILES_CHKSUM = "file://COPYING;md5=393a5ca445f6965873eca0259a17f833"

meta-gpe/recipes-graphics/libgpewidget/libgpewidget_0.117.bb

@@ -1,6 +1,5 @@
 DESCRIPTION = "libgpewidget contains a collection of widgets and other common code shared by many GPE applications."
 SECTION = "gpe/libs"
-PRIORITY = "optional"
 
 LICENSE = "LGPLv2.1"
 LIC_FILES_CHKSUM = "file://COPYING.LIB;md5=d8045f3b8f929c1cb29a1e3fd737b499"