Add ASIC_REV_5752 definition.

Track-down all references to ASIC_REV_5750 and mirror them with
references to the newly defined ASIC_REV_5752.
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>