base-files: Fix override syntax

Signed-off-by: Andrei Gherzan <andrei.gherzan@huawei.com>

meta-oniro-staging/recipes-core/base-files/base-files_%.bbappend

-FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"
+FILESEXTRAPATHS:prepend := "${THISDIR}/${PN}:"
 
-SRC_URI_append = "file://profile.d/tmout.sh"
+SRC_URI:append = "file://profile.d/tmout.sh"
 
-do_install_append () {
+do_install:append () {
     sed -i 's/umask.*/umask 027/g' ${D}/${sysconfdir}/profile
     install -d ${WORKDIR}/profile.d/ ${D}${sysconfdir}/profile.d/
     install -m 0644 ${WORKDIR}/profile.d/tmout.sh ${D}${sysconfdir}/profile.d/tmout.sh