libubootenv: git define PV

The devtool workflow does not work without setting PV properly.

To prefer the git version add the following line to the distro config:
  PREFERRED_VERSION_libubootenv = "0.1+git%"

Signed-off-by: Adrian Freihofer <adrian.freihofer@siemens.com>

recipes-bsp/libubootenv/libubootenv_git.bb

@@ -1,5 +1,5 @@
 require libubootenv.inc
 SRCREV = "92949816720d7af2ac722016e7a5b9a85ff141bc"
-PV_append = "+git${SRCPV}"
+PV = "0.1+git${SRCPV}"
 
 DEFAULT_PREFERENCE = "-1"