MINOR: pools: rename CONFIG_HAP_LOCAL_POOLS to CONFIG_HAP_POOLS

MINOR: pools: rename CONFIG_HAP_LOCAL_POOLS to CONFIG_HAP_POOLS

We're going to make the local pool always present unless pools are
completely disabled. This means that pools are always enabled by
default, regardless of the use of threads. Let's drop this notion
of "local" pools and make it just "pool". The equivalent debug
option becomes DEBUG_NO_POOLS instead of DEBUG_NO_LOCAL_POOLS.

For now this changes nothing except the option and dropping the
dependency on USE_THREAD.