arm64: dts: renesas: Add ulcb{-kf} Audio Graph Card2 dtsi

arm64: dts: renesas: Add ulcb{-kf} Audio Graph Card2 dtsi

ALSA SoC has many types of Generic Audio Card drivers (Simple Audio
Card, Audio Graph Card, Audio Graph Card2), and Renesas/Kuninori
Morimoto wants to test these.

The Generic Audio Card driver had been requested on ALSA SoC.
It supports many types of device connection methods, and historically,
the requested connection support range of the generic driver has been
upgraded.

Upgrading the connection support range itself could not be implemented
in the generic driver, because we need to keep compatibility with old
DTBs. This is one of the reasons why we have many types of Generic Audio
Card driver.

The ULCB/KF combo is a good board stack to test these.
Kuninori has been testing these Generic Audio Card drivers by using his
local patches to switching drivers.  But from an information sharing
point of view, it is a good idea to upstream these, because the DT
configuration is complex.  Hence this can be a good sample for the user.

Hence add an "Audio Graph Card2" DT setting file for ULCB/KF,
and switch to use it.  You can switch to a different Generic Audio Graph
driver by updating ulcb.dtsi / ulcb-kf.dtsi.

From a normal user point of view who doesn't need to test the driver,
everything should stay as-is, and nothing changes.

Note that because this needs "switching driver", and not "adding extra
feature", this does not use a Device Tree overlay.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/87a62ni40z.wl-kuninori.morimoto.gx@renesas.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>