Provide workaround for the ages old bug affecting certain BCM5708S

Provide workaround for the ages old bug affecting certain BCM5708S
chip revision often found in the blades and resulting in interfaces
not sensing carrier signal. Looking at all problem reports it
appears that it only affects some very specific silicon revision
(ASIC (0x57081021); Rev (B2)) and version of the PHY that
supports 1000baseSX-FDX media only. Therefore, narrow the scope of
workaround to combination of that revision and media type. Given
that the first report on this issue is dated back to 2007, there is
not much hope that this issue will ever be properly resolved.

Among affected systems are IBM HS21, Intel SBXD132 and HP BL460c.

PR:		118238, 122551, 140970
MFC after:	1 month