USB: serial: add Fintek F81532/534 driver

This driver is for Fintek F81532/F81534 USB to Serial Ports IC.

F81532 spec:
https://drive.google.com/file/d/0B8vRwwYO7aMFOTRRMmhWQVNvajQ/view?usp=
sharing

F81534 spec:
https://drive.google.com/file/d/0B8vRwwYO7aMFV29pQWJqbVBNc00/view?usp=
sharing

Features:
1. F81532 is 1-to-2 & F81534 is 1-to-4 serial ports IC
2. Support Baudrate from B50 to B115200.
Signed-off-by: Ji-Ze Hong (Peter Hong) <hpeter+linux_kernel@gmail.com>
Signed-off-by: Johan Hovold <johan@kernel.org>

drivers/usb/serial/Kconfig

@@ -255,6 +255,16 @@ config USB_SERIAL_F81232
 	  To compile this driver as a module, choose M here: the
 	  module will be called f81232.
 
+config USB_SERIAL_F8153X
+	tristate "USB Fintek F81532/534 Multi-Ports Serial Driver"
+	help
+	  Say Y here if you want to use the Fintek F81532/534 Multi-Ports
+	  USB to serial adapter.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called f81534.
+
+
 config USB_SERIAL_GARMIN
        tristate "USB Garmin GPS driver"
        help

drivers/usb/serial/Makefile

@@ -23,6 +23,7 @@ obj-$(CONFIG_USB_SERIAL_EDGEPORT)		+= io_edgeport.o
 obj-$(CONFIG_USB_SERIAL_EDGEPORT_TI)		+= io_ti.o
 obj-$(CONFIG_USB_SERIAL_EMPEG)			+= empeg.o
 obj-$(CONFIG_USB_SERIAL_F81232)			+= f81232.o
+obj-$(CONFIG_USB_SERIAL_F8153X)			+= f81534.o
 obj-$(CONFIG_USB_SERIAL_FTDI_SIO)		+= ftdi_sio.o
 obj-$(CONFIG_USB_SERIAL_GARMIN)			+= garmin_gps.o
 obj-$(CONFIG_USB_SERIAL_IPAQ)			+= ipaq.o