gpio: npcm: Add SGPIO support for Nuvoton NPCM SoCs

Add Nuvoton BMC NPCM7xx/NPCM8xx sgpio driver.
BMC can use this driver to increase 64 GPI pins and 64 GPO pins to use.

Signed-off-by: Jim Liu <JJLIU0@nuvoton.com>
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index fcca694..d735877 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -301,6 +301,15 @@
 	  Support GPIO controllers on Nuvovon NPCM SoCs.
 	  NPCM7xx/NPCM8xx contain 8 GPIO banks, each bank contains 32 pins.
 
+config NPCM_SGPIO
+	bool "Nuvoton NPCM SGPIO driver"
+	depends on DM_GPIO
+	help
+	  Support Nuvoton BMC NPCM7xx/NPCM8xx sgpio driver support.
+	  Nuvoton NPCM SGPIO module is combine serial to parallel IC (HC595)
+	  and parallel to serial IC (HC165).
+	  BMC can use this driver to increase 64 GPI pins and 64 GPO pins to use.
+
 config OMAP_GPIO
 	bool "TI OMAP GPIO driver"
 	depends on ARCH_OMAP2PLUS