When debugging various issues, per IO channel IO statistics were useful
to understand what was happening. However, many of the stats were on a
port basis rather than an io channel basis.

Move statistics to an io channel basis.
Signed-off-by: NDick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: NJames Smart <james.smart@broadcom.com>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>