Add the layer meta-skeleton

Add the layer meta-skeleton, it will be used to place the various
canonical examples.

(From OE-Core rev: 3ccbfdecd0cd6c6d1476600b868647a9af46742e)

Signed-off-by: Robert Yang <liezhi.yang@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta-skeleton/conf/layer.conf

@@ -0,0 +1,10 @@
+# We have a conf and classes directory, add to BBPATH
+BBPATH := "${BBPATH}:${LAYERDIR}"
+
+# We have a packages directory, add to BBFILES
+BBFILES := "${BBFILES} ${LAYERDIR}/recipes-*/*/*.bb"
+
+BBFILE_COLLECTIONS += "skeleton"
+BBFILE_PATTERN_skeleton := "^${LAYERDIR}/"
+BBFILE_PRIORITY_skeleton = "1"
+