media: usb: dvb-usb-v2: af9035: let subdrv autoselect enable si2168 and si2157

The Logilink VG0022A DVB-T2 stick has these three devices. So to enable
support for this stick in the presence of MEDIA_SUBDRV_AUTOSELECT,
let DVB_USB_AF9035 select the two other drivers.

Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>