mlx5e: add add missing BH locking around napi_schdule()

It's not correct to call napi_schedule() in pure process
context. Because we use __raise_softirq_irqoff() we require
callers to be in a context which will eventually lead to
softirq handling (hardirq, bh disabled, etc.).

With code as is users will see:

 NOHZ tick-stop error: Non-RCU local softirq work is pending, handler #08!!!

Fixes: a8dd7ac1

 ("net/mlx5e: Generalize RQ activation")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>