V4L/DVB (6699): pvrusb2: Use of virtual IR chip is a device-specific attribute

For Hauppauge 24xxx devices, the IR receiver is a custom piece of
logic that is very specific to the device.  The pvrusb2 driver can
virtualize this to make it look like a more normal IR receiver found
in other Hauppauge devices.  The decision of whether or not to enable
this virtualization however is a device-specific attribute, thus this
changeset.

Signed-off-by: Mike Isely <isely@pobox.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>