arm64: dts: renesas: rzg2ul-smarc: Move spi1 pinmux to carrier board DTSI

spi1 is available on the RZ/G2UL SMARC EVK carrier board (PMOD0), hence
moving the spi1 pinmux from SoM to carrier board. This is to keep
consistency with the other SMARC EVKs.

Also while moving the pinmux rename rspi1 to spi1 to be consistent with
other SMARC EVK DTSIs.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20220921082221.10599-1-prabhakar.mahadev-lad.rj@bp.renesas.com


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