linux-imx

sfc: replace spinlocks with bit ops for busy poll locking

This patch reduces the overhead of locking for busy poll.
Previously the state was protected by a lock, whereas now
it's manipulated solely with atomic operations.

Signed-off-by: Shradha Shah <sshah@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>