MIPS: XLR, XLS: Add comment for smp setup

It seems that BSP could be setup twice, but the nlm_cpu_ready array is only
set for ASPs in smpboot.S, not including BSP.

Signed-off-by: Hillf Danton <dhillf@gmail.com>
Cc: "Jayachandran C." <jayachandranc@netlogicmicro.com>
Cc: LKML <linux-kernel@vger.kernel.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2695/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>,

arch/mips/netlogic/xlr/smp.c

@@ -158,6 +158,10 @@ void __init nlm_smp_setup(void)
 
 	num_cpus = 1;
 	for (i = 0; i < NR_CPUS; i++) {
+		/*
+		 * BSP is not set in nlm_cpu_ready array, it is only for
+		 * ASPs (goto see smpboot.S)
+		 */
 		if (nlm_cpu_ready[i]) {
 			cpu_set(i, phys_cpu_present_map);
 			__cpu_number_map[i] = num_cpus;