spi: dt-bindings: spi-sg2044-nor: Add SOPHGO SG2042

Add bindings for the SOPHGO SG2042 SPI-NOR flash controller,
which is compatible with SOPHGO SG2044.

Signed-off-by: Zixian Zeng <sycamoremoon376@gmail.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Chen Wang <unicorn_wang@outlook.com>
Link: https://patch.msgid.link/20250525-sfg-spifmc-v2-1-a3732b6f5ab4@gmail.com


Signed-off-by: Mark Brown <broonie@kernel.org>