spi: nuvoton: add NPCM PSPI controller driver

Add Nuvoton NPCM BMC Peripheral SPI controller driver.
NPCM750 include two general-purpose SPI interface.

Signed-off-by: Jim Liu <JJLIU0@nuvoton.com>
Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 2f12081..fcf67de 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -321,6 +321,11 @@
 	  This enables support for the Flash Interface Unit SPI controller
 	  in master mode.
 
+config NPCM_PSPI
+	bool "PSPI driver for Nuvoton NPCM SoC"
+	help
+	  PSPI driver for NPCM SoC
+
 config NXP_FSPI
 	bool "NXP FlexSPI driver"
 	depends on SPI_MEM