bnx2x: New link code

bnx2x: New link code

New Link code:
Moving all the link related code (including the calculations, the
initialization of the MAC and PHY and the external PHY's code) into
a separated file. The changes from the code that used to be part of
bnx2x.c (now called bnx2x_main.c) are:
- Using separate structures for link inputs and link outputs to clearly
  identify what was configured and what is the outcome
- Adding code to read external PHY FW version and print it as part of
  ethtool -i
- Adding code to upgrade external PHY FW from ethtool -E with special
  magic number - Changing the link down indication to ERR level
- Adding a lock on all PHY access to prevent an interrupt and
  setting changes to overlap
- Adding support for emulation and FPGA (small chunk of code that really
  helps in the lab) - Adding support for 1G on BCM8706 PHY
- Adding clear debug print incase of fan failure (the PHY type is now
  "failure")

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>