qede: Fix concurrency issue in PTP Tx path processing.

PTP Tx timestamping data structures are not protected against the
concurrent access in the Tx paths. Protecting the same using atomic
bit locks.

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>