arm64: dts: renesas: rzg2lc-smarc: Include SoM DTSI into board DTS

arm64: dts: renesas: rzg2lc-smarc: Include SoM DTSI into board DTS

Move including the rzg2lc-smarc-som.dtsi from the carrier board
rzg2lc-smarc.dtsi to the actual RZ/G2LC SMARC EVK board dts
r9a07g044c2-smarc.dts. Also move the SW1 related macros along with
PMOD1_SER0 to board dts so that we have all the configuration options
in the same file.

This patch is to keep consistency with other SMARC EVKs (RZ/G2L, RZ/G2UL)
and it makes sense not include the SoM into the carrier board as we might
in future have a different carrier board with the same SoM.

Suggested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20220919092130.93074-1-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>