MIPS: Replace setup_irq() by request_irq()

request_irq() is preferred over setup_irq(). Invocations of setup_irq()
occur after memory allocators are ready.

Per tglx[1], setup_irq() existed in olden days when allocators were not
ready by the time early interrupts were initialized.

Hence replace setup_irq() by request_irq().

remove_irq() has been replaced by free_irq() as well.

There were build error's during previous version, couple of which was
reported by kbuild test robot <lkp@intel.com> of which one was reported
by Thomas Bogendoerfer <tsbogend@alpha.franken.de> as well. There were a
few more issues including build errors, those also have been fixed.

[1] https://lkml.kernel.org/r/alpine.DEB.2.20.1710191609480.1971@nanos

Signed-off-by: afzal mohammed <afzal.mohd.ma@gmail.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

arch/mips/cobalt/irq.c

@@ -45,18 +45,20 @@ asmlinkage void plat_irq_dispatch(void)
 		spurious_interrupt();
 }
 
-static struct irqaction cascade = {
-	.handler	= no_action,
-	.name		= "cascade",
-	.flags		= IRQF_NO_THREAD,
-};
-
 void __init arch_init_irq(void)
 {
 	mips_cpu_irq_init();
 	gt641xx_irq_init();
 	init_i8259_irqs();
 
-	setup_irq(GT641XX_CASCADE_IRQ, &cascade);
-	setup_irq(I8259_CASCADE_IRQ, &cascade);
+	if (request_irq(GT641XX_CASCADE_IRQ, no_action, IRQF_NO_THREAD,
+			"cascade", NULL)) {
+		pr_err("Failed to request irq %d (cascade)\n",
+		       GT641XX_CASCADE_IRQ);
+	}
+	if (request_irq(I8259_CASCADE_IRQ, no_action, IRQF_NO_THREAD,
+			"cascade", NULL)) {
+		pr_err("Failed to request irq %d (cascade)\n",
+		       I8259_CASCADE_IRQ);
+	}
 }