dt-bindings: thermal: rcar-thermal: add R8A77995 support

Update rcar thermal dt-binding to  add R8A77995 info.

Signed-off-by: Yoshihiro Kaneko <ykaneko0929@gmail.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>