net/ice/base: search field vector indices for result slots

Previously, switch code would use only pre-reserved index
slots at the end of each field vector for recipe result index
locations. This patch adds code that detects other internal
empty index slots that could potentially be used. For each
recipe that is added, a determ ination is made as to whether
any of these additional index slots alige with all the profiles
selected for the recipe; if alignment is achieved, then these
result index slots can be used.

Signed-off-by: Dan Nowlin <dan.nowlin@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>
Acked-by: Qiming Yang <qiming.yang@intel.com>