Remove uses of PRINC

PRINC is now obsolete and the PR Service should be used instead to keep PR
values incrementing on change.

A patch has also been submitted to openembedded-core to bump the appropriate PR
values so that PR doesn't move backwards. This patch should only be applied
after that patch, and only to branches which include that patch (ie. if that
patch doesn't go into daisy in oe-core, this patch shouldn't go into daisy in
meta-raspberrypi).

Change-Id: Ibac9e4e89d12dbd6e94430f47e20b82a67506625
Signed-off-by: Paul Barker <paul@paulbarker.me.uk>
Acked-by: Andrei Gherzan <andrei@gherzan.ro>

recipes-bsp/formfactor/formfactor_0.0.bbappend

@@ -1,2 +1 @@
 FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"
-PRINC = "1"

recipes-graphics/xorg-xserver/xserver-xf86-config_0.1.bbappend

@@ -1,8 +1,5 @@
 FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"
 
-# Don't forget to bump PRINC if you update the extra files.
-PRINC := "${@int(PRINC) + 5}"
-
 THISDIR := "${@os.path.dirname(bb.data.getVar('FILE', d, True))}"
 FILESPATH =. "${@base_set_filespath(["${THISDIR}/${PN}"], d)}:"