vdpa/mlx5: fix overflow in queue attribute

vdpa/mlx5: fix overflow in queue attribute

The mlx5_vdpa_event_qp_create function makes shifting to the numeric
constant 1, then multiplies it by another constant and finally assigns
it into a uint64_t variable.

The numeric constant type is an int with a 32-bit sign. if after
shifting , its MSB (bit of sign) will change, the uint64 variable will
get into it a different value than what the function intended it to get.

Set the numeric constant 1 to be uint64_t in the first place.

Fixes: 8395927cdfaf ("vdpa/mlx5: prepare HW queues")
Cc: stable@dpdk.org
Signed-off-by: Michael Baum <michaelba@nvidia.com>
Acked-by: Matan Azrad <matan@nvidia.com>