net: mvpp2x: fix traffic stuck after PHY start error

net: mvpp2x: fix traffic stuck after PHY start error

Issue:
- Network stuck if autonegotion fails.

Issue root cause:

- When autonegotiation fails during port open procedure, the packet
  processor configuration does not finish and open procedure exits
  with error.
- However, this doesn't prevent u-boot network framework from
  calling send and receive procedures.
- Using transmit and receive functions of misconfigured packet
  processor will cause traffic to get stuck.

Fix:

- Continue packet processor configuration even if autonegotiation
  fails.  Only error message is triggered in this case.
- Exit transmit and receive functions if there is no PHY link
  indication.
- U-boot network framework now calls open procedure again during next
  transmit initiation.

Signed-off-by: Stefan Chulski <[email protected]>
Reviewed-by: Igal Liberman <[email protected]>
Tested-by: Igal Liberman <[email protected]>
Reviewed-by: Ramon Fried <[email protected]>
Acked-by: Joe Hershberger <[email protected]>