qede: get_channels() need to populate max tx/rx coalesce values

Recent changes in kernel ethtool implementation requires the driver
callback for get_channels() has to populate the values for max tx/rx
coalesce fields.

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>