libgpiod: improve FILESEXTRAPATHS

* I thought that PN in FILESEXTRAPATHS worked as everywhere else and
  as described in:
  https://lore.kernel.org/all/2261745fc01a4e3887ee98f98a425e88@vivavis.com/T/

* but surprisingly (to me)
  FILESEXTRAPATHS:prepend := "${THISDIR}/${PN}-2.x:"
  ends with effectively ${BPN}-2.x in bitbake -e (and the build doesn't fail
  to fetch file://gpio-manager.init in lib32-libgpiod build

* I've tried with kirkstone and dunfell as well and it ends with
  "libgpiod-2.x" for all 3 PNs:
  dunfell $ grep ^FILESEXTRAPATHS= env.* | sed 's@/OE.*dunfell/@@g'
  env.lib32-libgpiod:FILESEXTRAPATHS="meta-oe/meta-oe/recipes-support/libgpiod/libgpiod-2.x:__default:"
  env.libgpiod:FILESEXTRAPATHS="meta-oe/meta-oe/recipes-support/libgpiod/libgpiod-2.x:__default:"
  env.libgpiod-native:FILESEXTRAPATHS="meta-oe/meta-oe/recipes-support/libgpiod/libgpiod-2.x:__default:"

  dunfell $ grep ^PN= env.*
  env.lib32-libgpiod:PN="lib32-libgpiod"
  env.libgpiod:PN="libgpiod"
  env.libgpiod-native:PN="libgpiod-native"

  There is the QA check for PN in SRC_URI, maybe I took it a bit
  further and updated all FILESEXTRAPATHS references as well in our
  layers (in 2023) even when it wasn't causing build failures, e.g.:
  https://github.com/webosose/meta-webosose/commit/38d3cbf010a5e4e112d82ee473eecc718d9cc687

* so it's not so important to use BPN, but it's a bit clearer as that's
  what it ends evaluated into and what default FILESPATH is using as well:

  meta/classes-global/base.bbclass:FILESPATH = "${@base_set_filespath(["${FILE_DIRNAME}/${BP}", "${FILE_DIRNAME}/${BPN}", "${FILE_DIRNAME}/files"], d)}"
  meta/conf/bitbake.conf:#FILESPATH = "${FILE_DIRNAME}/${PF}:${FILE_DIRNAME}/${P}:${FILE_DIRNAME}/${PN}:${FILE_DIRNAME}/${BP}:${FILE_DIRNAME}/${BPN}:${FILE_DIRNAME}/files:${FILE_DIRNAME}"

  BPN was added in denzil 2009 (and FILESPATH moved to base.bbclass,
  bitbake.conf has commented-out value since then):
  https://git.openembedded.org/openembedded-core/commit/?h=denzil&id=94c895aad5ad286f172b04bc33ba670220d5eba8

  PF was dropped in dylan 2012:
  https://git.openembedded.org/openembedded-core/commit/?h=dylan&id=3efa13cd76bbd5611805021945fc9def88d9fd93

  P and PN were dropped shortly after in dylan 2012:
  https://git.openembedded.org/openembedded-core/commit/?h=dylan&id=fb359583b659cda643973fa285002aaffb729a51

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

meta-oe/recipes-support/libgpiod/libgpiod_1.6.5.bb

@@ -7,7 +7,7 @@ SRC_URI += "file://0001-bindings-cxx-disable-tests.patch"
 
 SRC_URI[sha256sum] = "ae280f697bf035a1fb780c9972e5c81d0d2712b7ab6124fb3fba24619daa72bc"
 
-FILESEXTRAPATHS:prepend := "${THISDIR}/${PN}-1.x:"
+FILESEXTRAPATHS:prepend := "${THISDIR}/${BPN}-1.x:"
 
 inherit python3native
 

meta-oe/recipes-support/libgpiod/libgpiod_2.2.bb

@@ -9,7 +9,7 @@ LIC_FILES_CHKSUM = " \
     file://LICENSES/CC-BY-SA-4.0.txt;md5=fba3b94d88bfb9b81369b869a1e9a20f \
 "
 
-FILESEXTRAPATHS:prepend := "${THISDIR}/${PN}-2.x:"
+FILESEXTRAPATHS:prepend := "${THISDIR}/${BPN}-2.x:"
 
 SRC_URI += "file://gpio-manager.init"