Revert "os-release: only run bbappend on do_compile"

This reverts commit f2b07859cc9586f96b072678d1f5f4586e77850b.

This turned out to only help hide the issue. Builds would pass but the
os-release value in the flash image would not be correct when this bug
hit.

Change-Id: Ie06c8cc3fbb5201cba9f0702b00e4bfd72c3058a
diff --git a/recipes-core/os-release/os-release.bbappend b/recipes-core/os-release/os-release.bbappend
index 1c98781..c010146 100644
--- a/recipes-core/os-release/os-release.bbappend
+++ b/recipes-core/os-release/os-release.bbappend
@@ -13,7 +13,7 @@
     except:
         pass
 
-python do_compile_prepend() {
+python() {
     version_id = run_git(d, 'describe --dirty --long')
     if version_id:
         d.setVar('VERSION_ID', version_id)