enic: add adaptive coalescing intr for intx and msi poll

Adaptive interrupt coalescing is available for msix. This patch adds the support
for msi poll. Interface for adaptive interrupt coalescing is already added in
driver. We just did not enable it for legacy intr & msi.

enic_calc_int_moderation() & enic_set_int_moderation() are defined as static
after enic_poll. Since enic_poll needs it, move both of these function
definitions above enic_poll. No change in functionality.

Signed-off-by: Govindarajulu Varadarajan <_govind@gmx.com>
Signed-off-by: David S. Miller <davem@davemloft.net>