arch/: Make sure the up_irq_enable() is available on all architectures. I will not be able to test all of these new versions of this function so this may break things for awhile.

arch/misoc/include/irq.h

@@ -70,6 +70,7 @@ extern "C"
 
 irqstate_t up_irq_save(void);
 void up_irq_restore(irqstate_t flags);
+irqstate_t up_irq_enable(void);
 
 #undef EXTERN
 #ifdef __cplusplus

arch/misoc/src/lm32/lm32_irq.c

@@ -82,6 +82,7 @@ void lm32_irq_initialize(void)
  * Name: up_irq_save
  *
  * Description:
+ *   Return the current interrupt enable state and disable all interrupts.
  *
  ****************************************************************************/
 
@@ -103,6 +104,7 @@ irqstate_t up_irq_save(void)
  * Name: up_irq_restore
  *
  * Description:
+ *   Restore saved interrupt state
  *
  ****************************************************************************/
 
@@ -113,6 +115,28 @@ void up_irq_restore(irqstate_t flags)
   irq_setie(flags);
 }
 
+/****************************************************************************
+ * Name: up_irq_enable
+ *
+ * Description:
+ *   Return the current interrupt enable state and enable all interrupts
+ *
+ ****************************************************************************/
+
+irqstate_t up_irq_restore(irqstate_t flags)
+{
+  irqstate_t flags;
+
+  /* Get the previous value of IE */
+
+  flags = irq_getie();
+
+  /* Enable interrupts and return the previous interrupt state */
+
+  irq_setie(1);
+  return flags;
+}
+
 /****************************************************************************
  * Name: up_disable_irq
  *