drm/i2c: tda9950: add CEC driver

Add a CEC driver for the TDA9950, which is a stand-alone I2C CEC device,
but is also integrated into HDMI transceivers such as the TDA9989 and
TDA19989.

The TDA9950 contains a command processor which handles retransmissions
and the low level bus protocol.  The driver just has to read and write
the messages, and handle error conditions.

Reviewed-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

include/linux/platform_data/tda9950.h

@@ -0,0 +1,16 @@
+#ifndef LINUX_PLATFORM_DATA_TDA9950_H
+#define LINUX_PLATFORM_DATA_TDA9950_H
+
+struct device;
+
+struct tda9950_glue {
+	struct device *parent;
+	unsigned long irq_flags;
+	void *data;
+	int (*init)(void *);
+	void (*exit)(void *);
+	int (*open)(void *);
+	void (*release)(void *);
+};
+
+#endif