irqdomain: Get rid of irq_create_identity_mapping()

The sole user of irq_create_identity_mapping() having been converted,
get rid of the unused helper.
Signed-off-by: Marc Zyngier <maz@kernel.org>

include/linux/irqdomain.h

@@ -419,12 +419,6 @@ extern int irq_create_strict_mappings(struct irq_domain *domain,
 				      unsigned int irq_base,
 				      irq_hw_number_t hwirq_base, int count);
 
-static inline int irq_create_identity_mapping(struct irq_domain *host,
-					      irq_hw_number_t hwirq)
-{
-	return irq_create_strict_mappings(host, hwirq, hwirq, 1);
-}
-
 extern const struct irq_domain_ops irq_domain_simple_ops;
 
 /* stock xlate functions */

kernel/irq/irqdomain.c

@@ -715,9 +715,6 @@ EXPORT_SYMBOL_GPL(irq_create_mapping_affinity);
  * locations. For use by controllers that already have static mappings
  * to insert in to the domain.
  *
- * Non-linear users can use irq_create_identity_mapping() for IRQ-at-a-time
- * domain insertion.
- *
  * 0 is returned upon success, while any failure to establish a static
  * mapping is treated as an error.
  */