python-scons*: upgrade to 2.5.1

Both python-scons and python-scons-native need to be upgraded to latest
upstream version.
This change was tested using qemux86 with core-image-sato.

(From OE-Core rev: b3dc1eb3baf54a313a9de03700d57f592bbd73b8)

Signed-off-by: Jose Lamego <jose.a.lamego@linux.intel.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-devtools/python/python-scons-native_2.5.1.bb

@@ -0,0 +1,8 @@
+require python-scons_${PV}.bb
+inherit native pythonnative
+DEPENDS = "python-native"
+RDEPENDS_${PN} = ""
+
+do_install_append() {
+    create_wrapper ${D}${bindir}/scons SCONS_LIB_DIR='${STAGING_DIR_HOST}/${PYTHON_SITEPACKAGES_DIR}'
+}