bnx2x: Fix Coalescing configuration

bnx2x drivers configure coalescing incorrectly (e.g., as a result of a call
to 'ethtool -c'). Although this is almost invisible to the user (due to NAPI)
designated tests will show the configuration is incorrect.

Signed-off-by: Dmitry Kravkov <dmitry@broadcom.com>
Signed-off-by: Yuval Mintz <yuvalmin@broadcom.com>
Signed-off-by: Ariel Elior <ariele@broadcom.com>
Signed-off-by: Eilon Greenstein <eilong@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>