arm, smp: Correctly transform irq index into ID

Under SMP configurations, getActiveIRQ doesn't directly return an IRQ
ID, but an encoding of the ID and core due to the existance of per core
interrupts. This fixes some remaining locations where the result is
still interpreted as an IRQ.

src/arch/arm/c_traps.c

@@ -95,7 +95,7 @@ void VISIBLE NORETURN c_handle_instruction_fault(void)
 
 void VISIBLE NORETURN c_handle_interrupt(void)
 {
-    NODE_LOCK_IRQ_IF(getActiveIRQ() != irq_remote_call_ipi);
+    NODE_LOCK_IRQ_IF(IDX_TO_IRQ(getActiveIRQ()) != irq_remote_call_ipi);
     c_entry_hook();
 
 #ifdef TRACK_KERNEL_ENTRIES