iavf: Prevent changing static ITR values if adaptive moderation is on

Resolve being able to change static values on VF when adaptive interrupt
moderation is enabled.

This problem is fixed by checking the interrupt settings is not
a combination of change of static value while adaptive interrupt
moderation is turned on.

Without this fix, the user would be able to change static values
on VF with adaptive moderation enabled.

Fixes: 65e87c03

 ("i40evf: support queue-specific settings for interrupt moderation")
Signed-off-by: Nitesh B Venkatesh <nitesh.b.venkatesh@intel.com>
Tested-by: George Kuruvinakunnel <george.kuruvinakunnel@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>