bnx2x: Move common function into aggregated function

Move all PHY specific logic from bnx2x_main into bnx2x_link.

Signed-off-by: Yaniv Rosner <yanivr@broadcom.com>
Signed-off-by: Eilon Greenstein <eilong@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>