No need to use irq_create_mapping (although there is no issue with
doing so) when we are only looking up an existing mapping. Just to
streamline things a little and make the code a little more clear
change some calls from irq_create_mapping to irq_find_mapping.
Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>