MIPS: Netlogic: Exclude netlogic,xlp-pic code from XLR builds

Code in arch/mips/netlogic/common/irq.c which handles the XLP PIC fails
to build in XLR configurations due to cpu_is_xlp9xx not being defined,
leading to the following build failure:

    arch/mips/netlogic/common/irq.c: In function ‘xlp_of_pic_init’:
    arch/mips/netlogic/common/irq.c:298:2: error: implicit declaration
    of function ‘cpu_is_xlp9xx’ [-Werror=implicit-function-declaration]
      if (cpu_is_xlp9xx()) {
      ^

Although the code was conditional upon CONFIG_OF which is indirectly
selected by CONFIG_NLM_XLP_BOARD but not CONFIG_NLM_XLR_BOARD, the
failing XLR with CONFIG_OF configuration can be configured manually or
by randconfig.

Fix the build failure by making the affected XLP PIC code conditional
upon CONFIG_CPU_XLP which is used to guard the inclusion of
asm/netlogic/xlp-hal/xlp.h that provides the required cpu_is_xlp9xx
function.

[ralf@linux-mips.org: Fixed up as per Jayachandran's suggestion.]
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Jayachandran C <jchandra@broadcom.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14524/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/netlogic/common/irq.c

@@ -275,7 +275,7 @@ asmlinkage void plat_irq_dispatch(void)
 	do_IRQ(nlm_irq_to_xirq(node, i));
 }
 
-#ifdef CONFIG_OF
+#ifdef CONFIG_CPU_XLP
 static const struct irq_domain_ops xlp_pic_irq_domain_ops = {
 	.xlate = irq_domain_xlate_onetwocell,
 };
@@ -348,7 +348,7 @@ void __init arch_init_irq(void)
 #if defined(CONFIG_CPU_XLR)
 	nlm_setup_fmn_irq();
 #endif
-#if defined(CONFIG_OF)
+#ifdef CONFIG_CPU_XLP
 	of_irq_init(xlp_pic_irq_ids);
 #endif
 }