[poky] [PATCH 1/1] bblayers.conf.sample: update BBPATH to use BBPATH_EXTRA

[Robert Yang]

So that user can easily make their own conf files such as conf/site.conf
When user sets BBPATH_EXTRA in env to their own dir which contains
conf/site.conf, it will work.

Note, BBPATH_EXTRA must end with ":", we can't set BBPATH as
"${BBPATH_EXTRA}:${TOPDIR}" since the sanity would fail when
BBPATH_EXTRA is null.

[YOCTO #7837]

Signed-off-by: Robert Yang <liezhi.yang at windriver.com>
---
 meta-poky/conf/bblayers.conf.sample | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/meta-poky/conf/bblayers.conf.sample b/meta-poky/conf/bblayers.conf.sample
index 8b1cbdf..3857656 100644
--- a/meta-poky/conf/bblayers.conf.sample
+++ b/meta-poky/conf/bblayers.conf.sample
@@ -2,7 +2,8 @@
 # changes incompatibly
 POKY_BBLAYERS_CONF_VERSION = "2"
 
-BBPATH = "${TOPDIR}"
+BBPATH_EXTRA ??= ""
+BBPATH = "${BBPATH_EXTRA}${TOPDIR}"
 BBFILES ?= ""
 
 BBLAYERS ?= " \
-- 
2.8.0