net/mlx5_core: Add helper function to read IB error counters

Added helper function to read IB standard error counters
via the PPCNT register.

The PPCNT register read command provides the 32-bit error counters
of both IB/RoCE link layer and transport layer.

Signed-off-by: Meny Yossefi <menyy@mellanox.com>
Signed-off-by: Majd Dibbiny <majd@mellanox.com>
Reviewed-by: Matan Barak <matanb@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>