ARM: Activate FIQs to avoid __irq_startup warnings

There is a new test in __irq_startup that the IRQ is activated, which
hasn't been the case for FIQs since they bypass some of the usual setup.

Augment enable_fiq to include a call to irq_activate to avoid the
warning.

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

arch/arm/kernel/fiq.c

@@ -57,6 +57,8 @@
 static unsigned long dfl_fiq_insn;
 static struct pt_regs dfl_fiq_regs;
 
+extern int irq_activate(struct irq_desc *desc);
+
 /* Default reacquire function
  * - we always relinquish FIQ control
  * - we always reacquire FIQ control
@@ -141,6 +143,8 @@ static int fiq_start;
 
 void enable_fiq(int fiq)
 {
+	struct irq_desc *desc = irq_to_desc(fiq + fiq_start);
+	irq_activate(desc);
 	enable_irq(fiq + fiq_start);
 }