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 referenced. Thanks to Phil Blundell for
the command.

(From OE-Core rev: d122343362669c683acc4af295971a62cbc823fc)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-devtools/bison/bison_2.3.bb

@@ -7,7 +7,6 @@ HOMEPAGE = "http://www.gnu.org/software/bison/"
 LICENSE = "GPLv2"
 LIC_FILES_CHKSUM = "file://COPYING;md5=eb723b61539feef013de476e68b5c50a"
 SECTION = "devel"
-PRIORITY = "optional"
 DEPENDS = "bison-native"
 
 PR = "r0"

meta/recipes-devtools/bison/bison_2.5.bb

@@ -7,7 +7,6 @@ HOMEPAGE = "http://www.gnu.org/software/bison/"
 LICENSE = "GPLv3"
 LIC_FILES_CHKSUM = "file://COPYING;md5=d32239bcb673463ab874e80d47fae504"
 SECTION = "devel"
-PRIORITY = "optional"
 DEPENDS = "bison-native"
 
 PR = "r0"