Adding eswitch statistics support. User can get
whole eswitch stats or stats of func belong to that eswitch.

Added:
o command to get statistics of eswitch and function.
o sysfs support to export eswitch and func statatistics.
Signed-off-by: NAmit Kumar Salecha <amit.salecha@qlogic.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>