irqdomain: Export irq_domain_update_bus_token

Add export for irq_domain_update_bus_token() so that
we can allow drivers like the qcom-pdc driver to be
loadable as a module.

Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Andy Gross <agross@kernel.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Maulik Shah <mkshah@codeaurora.org>
Cc: Lina Iyer <ilina@codeaurora.org>
Cc: Saravana Kannan <saravanak@google.com>
Cc: Todd Kjos <tkjos@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-arm-msm@vger.kernel.org
Cc: iommu@lists.linux-foundation.org
Cc: linux-gpio@vger.kernel.org
Link: https://lore.kernel.org/r/20200710231824.60699-2-john.stultz@linaro.org

kernel/irq/irqdomain.c

@@ -281,6 +281,7 @@ void irq_domain_update_bus_token(struct irq_domain *domain,
 
 	mutex_unlock(&irq_domain_mutex);
 }
+EXPORT_SYMBOL_GPL(irq_domain_update_bus_token);
 
 /**
  * irq_domain_add_simple() - Register an irq_domain and optionally map a range of irqs