at: Change when files are copied

The create_spdx code relies on patched code, if files are changed
or added during the do_configure phase they will be missed by the
create_spdx process. So we need to ensure files modifications/additions
happen in the do_patch phase.

(From OE-Core rev: 227c46fe48b64de7574f7b6b407b8c13be71b392)

Signed-off-by: Saul Wold <saul.wold@windriver.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-extended/at/at_3.2.5.bb

@@ -52,8 +52,10 @@ INITSCRIPT_PARAMS = "defaults"
 
 SYSTEMD_SERVICE:${PN} = "atd.service"
 
-do_configure:prepend() {
-	cp -f ${WORKDIR}/posixtm.[ch] ${S}
+do_patch[postfuncs] += "copy_posix_files"
+
+copy_posix_files() {
+    cp -f ${WORKDIR}/posixtm.[ch] ${S}
 }
 
 do_install () {