qed: Fix possible error in populating max_tc field.

qed: Fix possible error in populating max_tc field.

Orabug: 26783820

Some adapters may not publish the max_tc value. Populate the default
value for max_tc field in case the mfw didn't provide one.

Signed-off-by: Sudarsana Reddy Kalluru <Sudarsana.Kalluru@cavium.com>
Signed-off-by: Yuval Mintz <Yuval.Mintz@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[ Upstream commit 66367dab30c7040e638e5496a47184cfc8ba39a4 ]
Signed-off-by: Somasundaram Krishnasamy <somasundaram.krishnasamy@oracle.com>