V4L/DVB (13361): stv090x: fix TS corruption with High Symbol Rate streams

With a lower bandwidth setup, the Transport Stream gets corrupted due to
TSFIFO overrun. The patch fixes the issue.

The issue is seen with Transport Streams having a Symbol Rate of 22MSPS
and/or greater.

Signed-off-by: Manu Abraham <manu@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>