dt-bindings: timer: renesas,tmu: add r8a779a0 TMU support

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20210607124828.1984-1-wsa+renesas@sang-engineering.com


Signed-off-by: Rob Herring <robh@kernel.org>