dt-bindings: vendor-prefixes: Add prefix for Storopack

Add a vendor prefix entry for Storopack (https://www.storopack.com

).

Signed-off-by: Fabio Estevam <festevam@denx.de>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>