[TG3]: Add A1 revs

This patch adds the A1 revision of 5784, 5764, and 5761, and applies all
previous bugfixes.  In places where the list of devices gets too long,
the patch uses a new TG3_FLG3_5761_5784_AX_FIXES flag instead.

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