Without this, we get failures like this when the kernel attempts to
initialize a cx231xx device:

	[16046.153653] cx231xx 3-1.2:1.1: New device Hauppauge Hauppauge Device @ 480 Mbps (2040:c200) with 6 interfaces
	[16046.153900] cx231xx 3-1.2:1.1: can't change interface 3 alt no. to 3: Max. Pkt size = 0
	[16046.153907] cx231xx 3-1.2:1.1: Identified as Hauppauge USB Live 2 (card=9)
	[16046.154350] i2c i2c-11: Added multiplexed i2c bus 13
	[16046.154379] i2c i2c-11: Added multiplexed i2c bus 14
	[16046.267194] cx25840 10-0044: cx23102 A/V decoder found @ 0x88 (cx231xx #0-0)
	[16048.424551] cx25840 10-0044: loaded v4l-cx231xx-avcore-01.fw firmware (16382 bytes)
	[16048.463224] cx231xx 3-1.2:1.1: v4l2 driver version 0.0.3
	[16048.567878] cx231xx 3-1.2:1.1: Registered video device video2 [v4l2]
	[16048.568001] cx231xx 3-1.2:1.1: Registered VBI device vbi0
	[16048.568419] cx231xx 3-1.2:1.1: audio EndPoint Addr 0x83, Alternate settings: 3
	[16048.568425] cx231xx 3-1.2:1.1: video EndPoint Addr 0x84, Alternate settings: 5
	[16048.568431] cx231xx 3-1.2:1.1: VBI EndPoint Addr 0x85, Alternate settings: 2
	[16048.568436] cx231xx 3-1.2:1.1: sliced CC EndPoint Addr 0x86, Alternate settings: 2
	[16048.568448] usb 3-1.2: couldn't get decoder output pad for V4L I/O
	[16048.568453] cx231xx 3-1.2:1.1: V4L2 device vbi0 deregistered
	[16048.568579] cx231xx 3-1.2:1.1: V4L2 device video2 deregistered
	[16048.569001] cx231xx: probe of 3-1.2:1.1 failed with error -22

Likely a regession since Commit 9d6d20e6
("media: v4l2-mc: switch it to use the new approach to setup pipelines")
(v4.19-rc1-100-g9d6d20e6), which introduced the use of
PAD_SIGNAL_DV within v4l2_mc_create_media_graph().

This also modifies cx25840 to remove the VBI pad, matching the action
taken in Commit 092a3787 ("media: v4l2: remove VBI output pad").

Fixes: 9d6d20e6 ("media: v4l2-mc: switch it to use the new approach to setup pipelines")

Cc: stable@vger.kernel.org
Signed-off-by: Cody P Schafer <dev@codyps.com>
Tested-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>