genirq: deprecate __do_IRQ

Two years migration time is enough. Remove the compability cruft.

Add the deprecated warning in kernel/irq/handle.c because marking
__do_IRQ itself is way too noisy.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Documentation/feature-removal-schedule.txt

@@ -344,3 +344,11 @@ Why:	See commits 129f8ae9b1b5be94517da76009ea956e89104ce8 and
 	Removal is subject to fixing any remaining bugs in ACPI which may
 	cause the thermal throttling not to happen at the right time.
 Who:	Dave Jones <davej@redhat.com>, Matthew Garrett <mjg@redhat.com>
+
+-----------------------------
+
+What:	__do_IRQ all in one fits nothing interrupt handler
+When:	2.6.32
+Why:	__do_IRQ was kept for easy migration to the type flow handlers.
+	More than two years of migration time is enough.
+Who:	Thomas Gleixner <tglx@linutronix.de>

kernel/irq/handle.c

@@ -349,6 +349,11 @@ irqreturn_t handle_IRQ_event(unsigned int irq, struct irqaction *action)
 }
 
 #ifndef CONFIG_GENERIC_HARDIRQS_NO__DO_IRQ
+
+#ifdef CONFIG_ENABLE_WARN_DEPRECATED
+# warning __do_IRQ is deprecated. Please convert to proper flow handlers
+#endif
+
 /**
  * __do_IRQ - original all in one highlevel IRQ handler
  * @irq:	the interrupt number