V4L/DVB (9583): Remember chip id of devices at initialization

When setting up the device, remember the chip id, so we can control behavior
in the future without having to read the register continuously.
Signed-off-by: Devin Heitmueller <devin.heitmueller@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/em28xx/em28xx-cards.c

@@ -1319,6 +1319,7 @@ void em28xx_pre_card_setup(struct em28xx *dev)
 	dev->wait_after_write = 5;
 	rc = em28xx_read_reg(dev, EM28XX_R0A_CHIPID);
 	if (rc > 0) {
+		dev->chip_id = rc;
 		switch (rc) {
 		case CHIP_ID_EM2860:
 			em28xx_info("chip ID is em2860\n");

drivers/media/video/em28xx/em28xx.h

@@ -370,6 +370,7 @@ struct em28xx {
 	char name[30];		/* name (including minor) of the device */
 	int model;		/* index in the device_data struct */
 	int devno;		/* marks the number of this device */
+	enum em28xx_chip_id chip_id;
 	unsigned int is_em2800:1;
 	unsigned int has_msp34xx:1;
 	unsigned int has_tda9887:1;