[PATCH] tg3: capacitive coupling detection fix

This patch fixes the problem reported in:

http://marc.theaimsgroup.com/?l=linux-kernel&m=110798711911645&w=2


The 5700 link problem was caused by reading uninitialized values in sram and
causing capacitive coupling mode to be enabled by mistake. This patch fixes
the problem by properly validating the sram contents.


Signed-off-by: Michael Chan <mchan@broadcom.com>