dt-bindings: clock: ingenic: Add ingenic,jz4760{,b}-cgu compatibles

Add ingenic,jz4760-cgu and ingenic,jz4760b-cgu compatible strings for
the JZ4760 and JZ4760B SoCs respectively.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20210530164923.18134-2-paul@crapouillou.net
Signed-off-by: Stephen Boyd <sboyd@kernel.org>