rules: install dhcp-events.rules; order alphabetically

Add dhcp-events.rules to Makefile.am so it gets installed.

Also order the rule files alphabetically for easier review.

rules/Makefile.am

@@ -1,18 +1,19 @@
 ruledir = $(datadir)/suricata/rules
 
 dist_rule_DATA = \
+app-layer-events.rules \
 decoder-events.rules \
-stream-events.rules \
-smtp-events.rules \
-http-events.rules \
+dhcp-events.rules \
+dnp3-events.rules \
 dns-events.rules \
-tls-events.rules \
-modbus-events.rules \
-app-layer-events.rules \
 files.rules \
-dnp3-events.rules \
-ntp-events.rules \
+http-events.rules \
+ipsec-events.rules \
+kerberos-events.rules \
+modbus-events.rules \
 nfs-events.rules \
+ntp-events.rules \
 smb-events.rules \
-ipsec-events.rules \
-kerberos-events.rules
+smtp-events.rules \
+stream-events.rules \
+tls-events.rules