V4L/DVB: xc3028: fix regression in firmware loading time

Fix a regression in the firmware loading time where it went from 1080 ms to
4700 ms.  This was noticed when the em28xx based HVR-950 took noticably longer
to load the driver.

Regression introduced in hg 12824.  The developer added an msleep() call with
an argument based on a newly introduced xc3028_ctrl field, which is left
initialized to zero for pretty much every board that is currently supported.

Signed-off-by: Devin Heitmueller <dheitmueller@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>