doc: Setting Affinity to a Single Processor
score: Use _Per_CPU_Get_snapshot()
score: Simplify Giant lock
score: Delete superfluous assignments

These values are already zero initialized by C run-time setup.
score: Fix warning
score: Use common names for per-CPU variables

Use "cpu" for an arbitrary Per_CPU_Control variable.

Use "cpu_self" for the Per_CPU_Control of the current processor.

Use "cpu_index" for an arbitrary processor index.

Use "cpu_index_self" for the processor index of the current processor.

Use "cpu_count" for the processor count obtained via
_SMP_Get_processor_count().

Use "cpu_max" for the processor maximum obtained by
rtems_configuration_get_maximum_processors().
bsps/powerpc: Fix linker command files
bsp/mbx8xx: Fix Makefile.am and bsp_specs