dt-bindings: vendor-prefixes: Add Square

Add vendor prefix for Square (https://squareup.com

).

Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230407194905.611461-2-bryan.odonoghue@linaro.org