dts: riscv: gigadevice: gd32vf103: add spi1
dts: riscv: gigadevice: gd32vf103: add spi1

Add spi1 definition.

Signed-off-by: TOKITA Hiroshi <501187a43400793219de4d849513395616209606@gmail.com>

galak/zephyr,galak/zephyr,finikorg/zephyr,galak/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr