tg3: Fix 5717 and 57765 memory selftests

Both the 5717 and the 57765 will fail 'ethtool -t' selftests at the
memory selftest portion.  The memory map for these two devices differs
from the rest of the asic revs and each other.  This patch adds a new
memory map to use for memory selftests.

Signed-off-by: Matt Carlson <mcarlson@broadcom.com>
Reviewed-by: Michael Chan <mchan@broadcom.com>
Reviewed-by: Benjamin Li <benli@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>