dt-bindings: clock: r9a06g032: Add the definition of the watchdog clock

This clock is actually the REF_SYNC_D8 clock.

Signed-off-by: Jean-Jacques Hiblot <jjhiblot@traphandler.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220221095032.95054-2-jjhiblot@traphandler.com


Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>