arm64: dts: renesas: rzg2l-smarc: Add common dtsi file

arm64: dts: renesas: rzg2l-smarc: Add common dtsi file

RZ/{G2L,V2L} and G2LC SoC use the same carrier board, but the SoM is
different.

Different pin mapping is possible on SoM. For eg:- RZ/G2L SMARC EVK
uses SCIF2, whereas RZ/G2LC uses SCIF1 for the serial interface available
on PMOD1.

This patch adds support for handling the pin mapping differences by moving
definitions common to RZ/G2L and RZ/G2LC to a common dtsi file.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20220203170636.7747-2-biju.das.jz@bp.renesas.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>