dt-bindings: vendor-prefixes: Add EBS-SYSTART GmbH Vendor Prefix

Add vendor prefix for EBS-SYSTART GmbH.

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>