dt-bindings: vendor-prefixes: add Shift GmbH

Add prefix for SHIFT GmbH, phone manufacturer
(https://www.shiftphones.com/en/

).

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220521164550.91115-1-krzysztof.kozlowski@linaro.org


Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>