arm64: dts: renesas: Add initial support for RZ/G3S SMARC SoM

arm64: dts: renesas: Add initial support for RZ/G3S SMARC SoM

Add initial support for the RZ/G3S SMARC SoM.  The following devices
available on the SoM are added to this initial device tree:
  - RZ/G3S SoC: Renesas R9A08G045S33GBG
  - Clock Generator (only 24MHz output): Renesas 5L35023B
  - 1GiB LPDDR4 SDRAM: Micron MT53D512M16D1DS-046
  - 64GB eMMC Flash (though SD ch0): Micron MTFC64GBCAQTC

SD channel 0 of RZ/G3S is connected to an uSD card interface and an
eMMC.  The selection b/w them is done through a hardware switch.  The DT
will select b/w uSD and eMMC through the SW_SD0_DEV_SEL build flag.

Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20230929053915.1530607-25-claudiu.beznea@bp.renesas.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>