lisa.utils: Slightly improve FrozenDict hashing perf
lisa.utils: Slightly improve FrozenDict hashing perf

Remove a useless sorted() call, since key order is not taken into
account in __eq__ defintion for Mapping.

ARM-software/lisa,ARM-software/lisa,credp/lisa,credp/lisa,credp/lisa,ARM-software/lisa,credp/lisa,ARM-software/lisa