bnx2x: Reset PHY due to fan failure for 578xx

Add hardware PHY reset action for BCM578xx when fan failure occur.
The new bnx2x_warpcore_hw_reset warps bnx2x_warpcore_power_module to fit the .hw_reset function template of the phy structure.

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>