powerpc/85xx: Remove #ifdefs CONFIG_PPC_I8259 in mpc85xx_ds

All necessary items are declared all the time, no need to use
a #ifdef CONFIG_PPC_I8259.

Refactor CONFIG_PPC_I8259 actions into a dedicated init function.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230408140122.25293-6-pali@kernel.org

arch/powerpc/platforms/85xx/mpc85xx_ds.c

@@ -34,7 +34,6 @@
 
 #include "mpc85xx.h"
 
-#ifdef CONFIG_PPC_I8259
 static void mpc85xx_8259_cascade(struct irq_desc *desc)
 {
 	struct irq_chip *chip = irq_desc_get_chip(desc);
@@ -45,29 +44,16 @@ static void mpc85xx_8259_cascade(struct irq_desc *desc)
 	}
 	chip->irq_eoi(&desc->irq_data);
 }
-#endif	/* CONFIG_PPC_I8259 */
 
-void __init mpc85xx_ds_pic_init(void)
+static void __init mpc85xx_8259_init(void)
 {
-	struct mpic *mpic;
-	int flags = MPIC_BIG_ENDIAN | MPIC_SINGLE_DEST_CPU;
-#ifdef CONFIG_PPC_I8259
 	struct device_node *np;
 	struct device_node *cascade_node = NULL;
 	int cascade_irq;
-#endif
 
-	if (of_machine_is_compatible("fsl,MPC8572DS-CAMP"))
-		flags |= MPIC_NO_RESET;
-
-	mpic = mpic_alloc(NULL, 0, flags, 0, 256, " OpenPIC  ");
-
-	if (WARN_ON(!mpic))
+	if (!IS_ENABLED(CONFIG_PPC_I8259))
 		return;
 
-	mpic_init(mpic);
-
-#ifdef CONFIG_PPC_I8259
 	/* Initialize the i8259 controller */
 	for_each_node_by_type(np, "interrupt-controller")
 	    if (of_device_is_compatible(np, "chrp,iic")) {
@@ -92,7 +78,24 @@ void __init mpc85xx_ds_pic_init(void)
 	of_node_put(cascade_node);
 
 	irq_set_chained_handler(cascade_irq, mpc85xx_8259_cascade);
-#endif	/* CONFIG_PPC_I8259 */
+}
+
+void __init mpc85xx_ds_pic_init(void)
+{
+	struct mpic *mpic;
+	int flags = MPIC_BIG_ENDIAN | MPIC_SINGLE_DEST_CPU;
+
+	if (of_machine_is_compatible("fsl,MPC8572DS-CAMP"))
+		flags |= MPIC_NO_RESET;
+
+	mpic = mpic_alloc(NULL, 0, flags, 0, 256, " OpenPIC  ");
+
+	if (WARN_ON(!mpic))
+		return;
+
+	mpic_init(mpic);
+
+	mpc85xx_8259_init();
 }
 
 /*