systemd: Add kmod option

Without kmod, the udev daemon is unable to run builtin kmod operations
for loading modules on demand. This breaks automatic loading via
modalias, meaning hotplugged USB devices won't have their modules
loaded.

Change-Id: I4d79e7d1587d5ad1900e6fa347a7647fd867cd3c
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/recipes-core/systemd/systemd_%.bbappend b/recipes-core/systemd/systemd_%.bbappend
index f9d8301..0e76c2e 100644
--- a/recipes-core/systemd/systemd_%.bbappend
+++ b/recipes-core/systemd/systemd_%.bbappend
@@ -2,7 +2,7 @@
             "${exec_prefix}/lib/systemd/catalog/*.*.catalog"
 PACKAGES =+ "${PN}-catalog-extralocales"
 PACKAGECONFIG = "pam hostnamed networkd randomseed resolved sysusers timedated \
-                 timesyncd xz"
+                 timesyncd xz kmod"
 
 FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"
 SRC_URI += "file://default.network"