Squashed commit of the following:

sched/init/nx_bringup.c:  Fix a naming collision.
    sched/init:  Rename os_start() to nx_start()
    sched/init:  Rename os_smp* to nx_smp*
    sched/init:  Rename os_bringup to nx_bringup
    sched/init:  rename all internal static functions to begin with nx_ vs os_

arch/misoc/src/lm32/lm32_idle.c

@@ -76,7 +76,7 @@ void up_idle(void)
    */
 
   /* This is a kludge that I still don't understand.  The call to kmm_trysemaphore()
-   * in the os_start.c IDLE loop seems necessary for the good health of the IDLE
+   * in the nx_start.c IDLE loop seems necessary for the good health of the IDLE
    * loop.  When the work queue is enabled, this logic is removed from the IDLE
    * loop and it appears that we are somehow left idling with interrupts non-
    * functional. The following should be no-op, it just disables then re-enables

arch/misoc/src/lm32/lm32_vectors.S

@@ -178,7 +178,7 @@ _do_reset:
 	bi		.clearBSS
 
 .callMain:
-	bi		os_start
+	bi		nx_start
 
 .save_all:
 	addi	sp, sp, -136