apache2: create configuration file for systemd-tmpfiles

when use systemd as a system and service manager, systemd-tmpfiles will replace
/etc/init.d/populate-volatile.sh to handle temporary files, so we need to create
the configuration file for apache2

Signed-off-by: Roy Li <rongqing.li@windriver.com>
apache2: add apxs to SSTATE_SCAN_FILES

apxs is installed under /usr/bin/crossscripts of sysroot, its hardcode paths
should be handled when store or extracts the sstate archives.

Signed-off-by: Roy Li <rongqing.li@windriver.com>