net/mlx4_core: Update the HCA core clock frequency after INIT_PORT

The firmware might change the hca core clock frequency after the driver
issues the INIT_PORT command. Therefore we need to query the new
value again and save in to the cached dev caps.

Fixes: ddd8a6c1 ('net/mlx4_core: Read HCA frequency and map internal clock')
Signed-off-by: Majd Dibbiny <majd@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Amir Vadai <amirv@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>