dt-bindings: Add missing start and/or end of line regex anchors

dt-bindings: Add missing start and/or end of line regex anchors

json-schema patterns by default will match anywhere in a string, so
typically we want at least the start or end anchored. Fix the obvious
cases where the anchors were forgotten.

Acked-by: Matti Vaittinen <mazziesaccount@gmail.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20221118223728.1721589-1-robh@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>