devlink: fix typos in qed documentation

Review of the recently added documentation file for the qed driver
noticed a couple of typos. Fix them now.

Noticed-by: Michal Kalderon <mkalderon@marvell.com>
Fixes: 0f261c3c ("devlink: add a driver-specific file for the qed driver")
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>