[media] gspca: Fix ov519 i2c r/w not working when connected to a xhci host

Fix the ov519 driver not working (unable to talk to the sensor) when
plugged into a xhci host. The root cause here is that uhci/ohci/ehci
hosts typically will send any pending async requests every milli-second
and then go to sleep for the rest if the milli-second, where as xhci hosts
send them immediately, causing things to go too fast for the ov519 bridge.

This commit adds a few delays fixing this.

Signed-off-by: Wesley Post <pa4wdh@xs4all.nl>
[hdegoede@redhat.com: Also add delays to w996Xcf.c, as that needs them too]
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>