To update SP firmware from the HOST, Oracle is standardizing on the fwupdate utility. This utility is included in Oracle Solaris as part of the Oracle Hardware Management Pack (OHMP).
For more information on using the fwpudate utility that is included in Oracle Solaris 11.3, refer to "Update an Oracle ILOM Service Processor Using fwupdate" in the Oracle Server CLI Tools for Oracle Solaris 11.3 User Guide (http://docs.oracle.com/cd/E64576_01/html/E64582/gltkm.html#scrolltoc).
When you follow the steps in that procedure, and have obtained a desired firmware package, this is the command that will update the SP from the HOST:
fwupdate update sp-bios-firmware -n sp_bios -f firmware-package-file.pkg
firmware-package-file.pkg is the path to the firmware package for your server's SP.