STiH410: Add STi serial driver

This patch adds support to ASC (asynchronous serial controller)
driver, which is basically a standard serial driver. This IP
is common across other STMicroelectronics SoCs

Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
index b11f3ff..7cb0eaa 100644
--- a/drivers/serial/Kconfig
+++ b/drivers/serial/Kconfig
@@ -413,4 +413,12 @@
 	  If you have a machine based on a Marvell XScale PXA2xx CPU you
 	  can enable its onboard serial ports by enabling this option.
 
+config STI_ASC_SERIAL
+	bool "STMicroelectronics on-chip UART"
+	depends on DM_SERIAL && ARCH_STI
+	help
+	  Select this to enable Asynchronous Serial Controller available
+	  on STiH410 SoC. This is a basic implementation,  it supports
+	  following baudrate 9600, 19200, 38400, 57600 and 115200.
+
 endmenu