clk: renesas: rcar-gen3: Add ADG clocks

clk: renesas: rcar-gen3: Add ADG clocks

R-Car Sound needs to enable "ADG" on RMSTPCR9/SMSTPCR9 bit 22 to use
clk_i which came from the internal S0D4 or ZA2 clock.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Tested-by: Vincenzo De Michele <vincenzo.michele@davinci.de> # R-Car M3-N
Tested-by: Patrick Keil <patrick.keil@conti-engineering.com> # R-Car M3-N
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/87pm47prox.wl-kuninori.morimoto.gx@renesas.com
Link: https://lore.kernel.org/r/87o7jrpros.wl-kuninori.morimoto.gx@renesas.com
Link: https://lore.kernel.org/r/87mszbpron.wl-kuninori.morimoto.gx@renesas.com
Link: https://lore.kernel.org/r/87leevproh.wl-kuninori.morimoto.gx@renesas.com
Link: https://lore.kernel.org/r/87jzufprod.wl-kuninori.morimoto.gx@renesas.com
Link: https://lore.kernel.org/r/87il9zpro8.wl-kuninori.morimoto.gx@renesas.com
Link: https://lore.kernel.org/r/87h6pjpro4.wl-kuninori.morimoto.gx@renesas.com
Link: https://lore.kernel.org/r/87fs53prny.wl-kuninori.morimoto.gx@renesas.com
Link: https://lore.kernel.org/r/87edknprnt.wl-kuninori.morimoto.gx@renesas.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>