serial:st-asc: Add ST ASC driver.

This patch adds support to ASC (asynchronous serial controller)
driver, which is basically a standard serial driver. This IP is common
across all the ST parts for settop box platforms.

ASC is embedded in ST COMMS IP block. It supports Rx & Tx functionality.
It support all industry standard baud rates.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@st.com>
CC: Stephen Gallimore <stephen.gallimore@st.com>
CC: Stuart Menefy <stuart.menefy@st.com>
CC: Arnd Bergmann <arnd@arndb.de>
CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
index 6e73781..bdf5c0e 100644
--- a/drivers/tty/serial/Kconfig
+++ b/drivers/tty/serial/Kconfig
@@ -1497,6 +1497,22 @@
 	  If you have enabled the lpuart serial port on the Freescale SoCs,
 	  you can make it the console by answering Y to this option.
 
+config SERIAL_ST_ASC
+	tristate "ST ASC serial port support"
+	select SERIAL_CORE
+	help
+	  This driver is for the on-chip Asychronous Serial Controller on
+	  STMicroelectronics STi SoCs.
+	  ASC is embedded in ST COMMS IP block. It supports Rx & Tx functionality.
+	  It support all industry standard baud rates.
+
+	  If unsure, say N.
+
+config SERIAL_ST_ASC_CONSOLE
+	bool "Support for console on ST ASC"
+	depends on SERIAL_ST_ASC=y
+	select SERIAL_CORE_CONSOLE
+
 endmenu
 
 endif # TTY