score: Add and use RTEMS_ZERO_LENGTH_ARRAY
score: Static scheduler configuration

Do not allocate the scheduler control structures from the workspace.
This is a preparation step for configuration of clustered/partitioned
schedulers on SMP.
score: Simplify thread control initialization

The thread control block contains fields that point to application
configuration dependent memory areas, like the scheduler information,
the API control blocks, the user extension context table, the RTEMS
notepads and the Newlib re-entrancy support.  Account for these areas in
the configuration and avoid extra workspace allocations for these areas.

This helps also to avoid heap fragementation and reduces the per thread
memory due to a reduced heap allocation overhead.
score: Task get/set affinity

Make rtems_task_get_affinity() and rtems_task_set_affinity() available
on non-SMP configurations.  Allow larger CPU sets.
score: Add scheduler name
rtems: Add scheduler identification
rtems: Add scheduler get processors
rtems: Add task get/set scheduler
score: Add clustered/partitioned scheduling

Clustered/partitioned scheduling helps to control the worst-case
latencies in the system.  The goal is to reduce the amount of shared
state in the system and thus prevention of lock contention.  Modern
multi-processor systems tend to have several layers of data and
instruction caches.  With clustered/partitioned scheduling it is
possible to honour the cache topology of a system and thus avoid
expensive cache synchronization traffic.

We have clustered scheduling in case the set of processors of a system
is partitioned into non-empty pairwise-disjoint subsets.  These subsets
are called clusters.  Clusters with a cardinality of one are partitions.
Each cluster is owned by exactly one scheduler instance.
bsps/powerpc: SMP support for one TSEC driver