MIPS: Netlogic: Fix UP compilation on XLR

The commit 2a37b1ae "MIPS: Netlogic: Move from u32 cpumask to cpumask_t"
breaks uniprocessor compilation on XLR with:

arch/mips/netlogic/xlr/setup.c: In function 'prom_init':
arch/mips/netlogic/xlr/setup.c:196:6: error: unused variable 'i'

Fix by defining 'i' only when CONFIG_SMP is defined.
Signed-off-by: NJayachandran C <jchandra@broadcom.com>
Patchwork: http://patchwork.linux-mips.org/patch/4760/Signed-off-by: NJohn Crispin <blogic@openwrt.org>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

arch/mips/netlogic/xlr/setup.c

@@ -193,8 +193,11 @@ static void nlm_init_node(void)
 
 void __init prom_init(void)
 {
-	int i, *argv, *envp;		/* passed as 32 bit ptrs */
+	int *argv, *envp;		/* passed as 32 bit ptrs */
 	struct psb_info *prom_infop;
+#ifdef CONFIG_SMP
+	int i;
+#endif
 
 	/* truncate to 32 bit and sign extend all args */
 	argv = (int *)(long)(int)fw_arg1;