Add basic support for the RZ/G2LC SMARC EVK (based on R9A07G044C2):
- memory
- External input clock
- SCIF
- GbEthernet
- Audio Clock

It shares the same carrier board with RZ/G2L, but the pin mapping is
different.  Disable the device nodes which are not tested and delete the
corresponding pinctrl definitions.
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/20211216114305.5842-4-biju.das.jz@bp.renesas.comSigned-off-by: Geert Uytterhoeven <geert+renesas@glider.be>