drivers: spi: use dedicated init priority

A couple of SPI drivers use CONFIG_KERNEL_INIT_PRIORITY_DEVICE
as init priority for driver initialization. Let's change
it to the dedicated CONFIG_SPI_INIT_PRIORITY to make it
compatible with other ones.

Signed-off-by: Bartosz Bilas <bartosz.bilas@hotmail.com>
diff --git a/drivers/spi/spi_rv32m1_lpspi.c b/drivers/spi/spi_rv32m1_lpspi.c
index 3492903..b99d3c3 100644
--- a/drivers/spi/spi_rv32m1_lpspi.c
+++ b/drivers/spi/spi_rv32m1_lpspi.c
@@ -299,7 +299,7 @@
 			    &spi_mcux_data_##n,				\
 			    &spi_mcux_config_##n,			\
 			    POST_KERNEL,				\
-			    CONFIG_KERNEL_INIT_PRIORITY_DEVICE,		\
+			    CONFIG_SPI_INIT_PRIORITY,			\
 			    &spi_mcux_driver_api);			\
 									\
 	static void spi_mcux_config_func_##n(const struct device *dev)	\