dt-bindings: vendor-prefixes: Add Check Point

Check Point Software Technologies Ltd. is a company based in Israel and
USA. They manufacture network devices and provide software
products for IT security.

Signed-off-by: Pawel Dembicki <paweldembicki@gmail.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Rob Herring <robh@kernel.org>