V4L/DVB (8464): cx23885: Bugfix for concurrent use of /dev/video0 and /dev/video1

With the HVR1800, trying to use video0 and video1 simultaneously caused
buffer corruption in the PCIe bridge. This fix reallocates video1
buffer locations to avoid the issue.

Signed-off-by: Steven Toth <stoth@hauppauge.com>
Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>