[media] cx231xx: Allow some boards to not use I2C port 3

Some devices don't need to use it. So allow to just disable this logic.
Having it enabled on some devices cause power management to complain,
generating error -71.
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/cx231xx/cx231xx-avcore.c

@@ -1271,6 +1271,8 @@ int cx231xx_enable_i2c_port_3(struct cx231xx *dev, bool is_port_3)
 	int status = 0;
 	bool current_is_port_3;
 
+	if (dev->board.dont_use_port_3)
+		is_port_3 = false;
 	status = cx231xx_read_ctrl_reg(dev, VRT_GET_REGISTER,
 				       PWR_CTL_EN, value, 4);
 	if (status < 0)

drivers/media/video/cx231xx/cx231xx.h

@@ -357,6 +357,7 @@ struct cx231xx_board {
 	unsigned int valid:1;
 	unsigned int no_alt_vanc:1;
 	unsigned int external_av:1;
+	unsigned int dont_use_port_3:1;
 
 	unsigned char xclk, i2c_speed;