platform: Drop irqchip warm init and exit hooks

Now that driver lifecycle is managed from within the SBI irqchip core,
platforms need only to initialize the driver once during cold init.
Remove the remaining platform hooks that are no longer used.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

platform/fpga/ariane/platform.c

@@ -98,19 +98,11 @@ static int ariane_final_init(bool cold_boot)
 }
 
 /*
- * Initialize the ariane interrupt controller for current HART.
+ * Initialize the ariane interrupt controller during cold boot.
  */
-static int ariane_irqchip_init(bool cold_boot)
+static int ariane_irqchip_init(void)
 {
-	int ret;
-
-	if (cold_boot) {
-		ret = plic_cold_irqchip_init(&plic);
-		if (ret)
-			return ret;
-	}
-
-	return 0;
+	return plic_cold_irqchip_init(&plic);
 }
 
 /*

platform/fpga/openpiton/platform.c

@@ -131,19 +131,11 @@ static int openpiton_final_init(bool cold_boot)
 }
 
 /*
- * Initialize the openpiton interrupt controller for current HART.
+ * Initialize the openpiton interrupt controller during cold boot.
  */
-static int openpiton_irqchip_init(bool cold_boot)
+static int openpiton_irqchip_init(void)
 {
-	int ret;
-
-	if (cold_boot) {
-		ret = plic_cold_irqchip_init(&plic);
-		if (ret)
-			return ret;
-	}
-
-	return 0;
+	return plic_cold_irqchip_init(&plic);
 }
 
 /*