rtems: Add rtems_scheduler_get_processor()

Add rtems_scheduler_get_processor() as a replacement for
rtems_get_current_processor(). The rtems_get_current_processor() is a
bit orphaned. Adopt it by the Scheduler Manager. This is in line with
the glibc sched_getcpu() function.

Deprecate rtems_get_current_processor().

Update #3731.

bsps/powerpc/qoriq/start/bsprestart.c

@@ -69,7 +69,7 @@ static void restart_interrupt(void *arg)
   _SMP_barrier_State_initialize(&bs);
   _SMP_barrier_Wait(&restart_barrier, &bs, _SMP_Processor_count);
 
-  cpu_self_index = rtems_get_current_processor();
+  cpu_self_index = rtems_scheduler_get_processor();
   thread_index = cpu_self_index % QORIQ_THREAD_COUNT;
 
   if (cpu_self_index == 0) {

bsps/sparc/leon3/start/bspclean.c

@@ -48,7 +48,7 @@ void bsp_fatal_extension(
        * processor.
        */
       uint32_t max_wait = 1234567;
-      uint32_t self_cpu = rtems_get_current_processor();
+      uint32_t self_cpu = rtems_scheduler_get_processor();
       uint32_t cpu_count = rtems_get_processor_count();
       uint32_t halt_mask = 0;
       uint32_t i;