af9033: implement read_ber and read_ucblocks functions. Version 2 of patch that
reflects my findings on the behaviour of abort_cnt, err_cnt and bit_cnt:

- bit_cnt is always 0x2710 (10000)
- abort_cnt is between 0 and 0x2710
- err_cnt is between 0 and 640000 (= 0x2710 * 8 * 8)

in the current implementation BER is calculated as the number of bit errors per
processed bits, ignoring those bits that are already discarded and counted in
abort_cnt, i.e. UCBLOCKS.
Signed-off-by: Hans-Frieder Vogt <hfvogt@gmx.net>
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>