Add commands' enumerations and messages definitions for all existing
notify-enable commands across all protocols.

Link: https://lore.kernel.org/r/20200327143438.5382-3-cristian.marussi@arm.comReviewed-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: NSudeep Holla <sudeep.holla@arm.com>