Adjust the retry timeout and number of retries to speed up xc5000
firmware download.  With this change it goes from 4.2 seconds to 2.9.
The net time waited is pretty much the same, but we just poll more
often.

Tested at 250 KHz as well as 30 KHz.
Signed-off-by: NDevin Heitmueller <dheitmueller@kernellabs.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>