drivers: spi: rv32m1: Add driver for RV32M1 LPSPI

Add SPI driver and bindings for LPSPI peripheral for the RV32M1 SOC.
Based heavily on the existing mcux LPSPI driver.

Signed-off-by: Karsten Koenig <karsten.koenig.030@gmail.com>

soc/riscv/openisa_rv32m1/Kconfig.defconfig

@@ -161,6 +161,14 @@ config I2C_RV32M1_LPI2C
 
 endif # I2C
 
+if SPI
+
+config SPI_RV32M1_LPSPI
+	default y
+
+endif # SPI
+
+
 if FLASH
 
 config SOC_FLASH_RV32M1

soc/riscv/openisa_rv32m1/Kconfig.soc

@@ -10,6 +10,7 @@ config SOC_OPENISA_RV32M1_RISCV32
 	select XIP
 	select HAS_RV32M1_LPUART
 	select HAS_RV32M1_LPI2C
+	select HAS_RV32M1_LPSPI
 	select ATOMIC_OPERATIONS_C
 	select VEGA_SDK_HAL
 	select RISCV_SOC_INTERRUPT_INIT