dt-bindings: timer: renesas,cmt: R-Car V3U is R-Car Gen4

Despite the name, R-Car V3U is the first member of the R-Car Gen4
family. Hence move its compatible value to the R-Car Gen4 section.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220713100603.3391-3-wsa+renesas@sang-engineering.com


Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>