net/ice/base: add RSS key related macro and structures

net/ice/base: add RSS key related macro and structures

Add define for 52 byte RSS hash key size, and add struct
ice_aqc_get_set_rss_keys comments regarding setting 40 bytes and
52 byte hash key.

Signed-off-by: Paul Greenwalt <paul.greenwalt@intel.com>
Signed-off-by: Paul M Stillwell Jr <paul.m.stillwell.jr@intel.com>
Signed-off-by: Qi Zhang <qi.z.zhang@intel.com>
Reviewed-by: Qiming Yang <qiming.yang@intel.com>
Reviewed-by: Wenzhuo Lu <wenzhuo.lu@intel.com>