This issue is fixed in Oracle Solaris 11.2 SRU 14.
After using fwupdate to update the Oracle ILOM service processor of a remote system over the network, the system that has been updated does not automatically reboot.
Workaround
After performing a remote update of an Oracle ILOM SP, manually power cycle the remote system to enable the update. A power cycle is required to reset a service processor after a firmware update.