dt-bindings: vendor-prefixes: add Seeed Studio

Add the "seeed" vendor prefix for Seeed Technology Co., Ltd
Website: https://www.seeedstudio.com/



Signed-off-by: Marcin Sloniewski <marcin.sloniewski@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Alexandre Torgue <alexandre.torgue@st.com>