net/mlx4_core: Work properly with EQ numbers > 256 in SRIOV

The Firmware uses dynamic EQs allocation based on number of VFs and
max EQs that can be allocated. As a result, VF can have EQ numbers
that are larger than 256.

According to the firmware spec, the max value is limited to be 1024
(10 bits), adapt the relevant code accordingly. This bug was impossible
to hit prior to commit 7ae0e400

 ("net/mlx4_core: Flexible (asymmetric)
allocation of EQs and MSI-X vectors for PF/VFs") which actually enables
large number of EQs for VFs.

Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>