riscv: dts: sophgo: Enable SPI NOR node for SG2042_EVB_V2

riscv: dts: sophgo: Enable SPI NOR node for SG2042_EVB_V2

Enable SPI NOR node for SG2042_EVB_V2 device tree

According to SG2042_EVB_V2 schematic, SPI-NOR Flash cannot support QSPI
due to hardware design. Thus spi-(tx|rx)-bus-width must be set to 1.

Signed-off-by: Han Gao <rabenda.cn@gmail.com>
Signed-off-by: Zixian Zeng <sycamoremoon376@gmail.com>
Link: https://lore.kernel.org/r/20250916-sfg-spidts-v2-4-b5d9024fe1c8@gmail.com
Signed-off-by: Inochi Amaoto <inochiama@gmail.com>
Signed-off-by: Chen Wang <unicorn_wang@outlook.com>
Signed-off-by: Chen Wang <wangchen20@iscas.ac.cn>