irqdomain: Eliminate dedicated radix lookup functions

In preparation to remove the slow revmap path, eliminate the public
radix revmap lookup functions.  This simplifies the code and makes the
slowpath removal patch a lot simpler.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Rob Herring <rob.herring@calxeda.com>

arch/powerpc/sysdev/xics/icp-hv.c

@@ -111,7 +111,7 @@ static unsigned int icp_hv_get_irq(void)
 	if (vec == XICS_IRQ_SPURIOUS)
 		return NO_IRQ;
 
-	irq = irq_radix_revmap_lookup(xics_host, vec);
+	irq = irq_find_mapping(xics_host, vec);
 	if (likely(irq != NO_IRQ)) {
 		xics_push_cppr(vec);
 		return irq;

arch/powerpc/sysdev/xics/icp-native.c

@@ -119,7 +119,7 @@ static unsigned int icp_native_get_irq(void)
 	if (vec == XICS_IRQ_SPURIOUS)
 		return NO_IRQ;
 
-	irq = irq_radix_revmap_lookup(xics_host, vec);
+	irq = irq_find_mapping(xics_host, vec);
 	if (likely(irq != NO_IRQ)) {
 		xics_push_cppr(vec);
 		return irq;