Unfortunately there is currently no way to do what you want entirely in Wildfly.
If you'll look in the default config, the port-offset is controlled at the socket-binding-group. It will increment every port in the group.
<socket-binding-group name="standard-sockets" default-interface="public" port-offset="${jboss.socket.binding.port-offset:0}">
And if you look in the XSD for the configuration you will see that the config only allows one socket-binding-group:
<xs:element name="socket-binding-group" type="standalone-socket-binding-groupType" minOccurs="0" maxOccurs="1"/>
Can I ask why you wouldn't want http to increment? If you are running multiple instances of WF on a server you always want all ports to increment. If you are only running one instance, you can configure all the ports directly in standalone.xml like this:
<socket-binding-group name="standard-sockets" default-interface="public" port-offset="${jboss.socket.binding.port-offset:0}">
<socket-binding name="management-http" interface="management" port="${jboss.management.http.port:9990}"/>
<socket-binding name="management-https" interface="management" port="${jboss.management.https.port:9993}"/>
<socket-binding name="ajp" port="${jboss.ajp.port:8009}"/>
<socket-binding name="http" port="7011"/>
<socket-binding name="https" port="7010"/>
<socket-binding name="txn-recovery-environment" port="4712"/>
<socket-binding name="txn-status-manager" port="4713"/>
<outbound-socket-binding name="mail-smtp">
<remote-destination host="localhost" port="25"/>
</outbound-socket-binding>
</socket-binding-group>
Then just leave the port offset at 0 and you are good.