dt/irq: add irq_domain_generate_simple() helper

irq_domain_generate_simple() is an easy way to generate an irq translation
domain for simple irq controllers.  It assumes a flat 1:1 mapping from
hardware irq number to an offset of the first linux irq number assigned
to the controller

Change-Id: I0820754314a0c15b1cc9881bc38b75b0de2509b2
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Sathish Ambley <sambley@codeaurora.org>
2 files changed