ARM: dts: r9a06g032: Describe the RTC

Describe the SoC RTC which counts time and provides alarm support.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20220429104602.368055-7-miquel.raynal@bootlin.com


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