dt-bindings: vendor-prefixes: Remove trailing whitespace

Fixes: f516fb70 ("dt-bindings: Whitespace clean-ups in schema files")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200819092058.1526-1-geert+renesas@glider.beSigned-off-by: Rob Herring <robh@kernel.org>