doc: update ice guide for MDD
doc: update ice guide for MDD

Update ICE document to describe a MDD event.

Signed-off-by: Wenzhuo Lu <58cb9036bdff9a5412edc3b9f70e105ccf59954f@intel.com>
Acked-by: Rami Rosen <d906574dd7f018d5d95e7b7a8107cdf708745f05@gmail.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk