[media] tvaudio: don't use thread for TA8874Z

Judging from the data sheet it will automatically switch to the next
best audio mode in accordance with the V4L2 tuner audio matrix.
Signed-off-by: Daniel Glöckner <daniel-gl@gmx.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/tvaudio.c

@@ -1597,7 +1597,6 @@ static struct CHIPDESC chiplist[] = {
 		.addr_lo    = I2C_ADDR_TDA9840 >> 1,
 		.addr_hi    = I2C_ADDR_TDA9840 >> 1,
 		.registers  = 2,
-		.flags      = CHIP_NEED_CHECKMODE,
 
 		/* callbacks */
 		.getmode    = ta8874z_getmode,