Add missed fields in documentation of plat_psci_ops
Add missed fields in documentation of plat_psci_ops

Change-Id: Ie4ee8aa2627573c95549927c9ac4e8a963035359
Signed-off-by: Roberto Vargas <d75e640c49defb97bd074f828210df57ed181e1f@arm.com>

lsigithub/arm-trusted-firmware_public,lsigithub/arm-trusted-firmware_public,achingupta/arm-trusted-firmware,achingupta/arm-trusted-firmware