mcelog: Install systemd service unit

Start mcelog during boot by systemd.

The unit still needs to be enabled though with `systemctl enable
mcelog`.

mcelog.be0

@@ -61,9 +61,11 @@ SRCURL[0]="https://git.kernel.org/pub/scm/utils/cpu/mce/mcelog.git/snapshot/mcel
 #    bee_build
 #}
 
-#mee_install() {
-#    bee_install
-#}
+mee_install() {
+    bee_install
+    install -v -m755 -d ${D}/lib/systemd/system
+    start_cmd install -v -m644 ${S}/mcelog.service ${D}/lib/systemd/system
+}
 ## by default this may be 'make install DESTDIR="${D}"'
 
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