common/mlx5: fix user mode register access attribute

common/mlx5: fix user mode register access attribute

To detect the timestamp mode configured on the NIC the mlx5 PMD uses the
firmware command ACCESS_REGISTER_USER.
The HCA capability command has an attribute flag checking whether
firmware supports the command.

However, the HCA capability query command read the flag from wrong place
in PRM structure.

This patch move the flag to correct place.

Fixes: 972a1bf8120d ("common/mlx5: fix user mode register access command")
Cc: stable@dpdk.org
Signed-off-by: Michael Baum <michaelba@nvidia.com>
Acked-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>