genirq/irq_sim: Return the base of the irq range from irq_sim_init()

Returning the base of the allocated interrupt range from irq_sim_init() and
devm_irq_sim_init() allows users to handle the logic of associating irq
numbers with any other driver-specific resources without having to use
irq_sim_irqnum().

Change-Id: I3f9ad370d739ba96b70330825721a458bd27b5bd
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/20180304121018.640-4-brgl@bgdev.pl
Git-commit: f09777fa891327ee0dd892e83619f156bf1c37e6
Git-repo: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


Signed-off-by: Vijay Navnath Kamble <vkambl@codeaurora.org>