of/irq: export of_get_irq_byname()

Similarly to of_get_irq(), let's export of_irq_get_byname(), so if a bus core
can be compiled as a module (such as I2C) it can have access to the symbol.

Reported-by: Stephen Rothwell <[e-mail]>
Reported-by: kbuild test robot <[e-mail]>
Signed-off-by: Dmitry Torokhov <[e-mail]>
Acked-by: Rob Herring <[e-mail]>
Signed-off-by: Wolfram Sang <[e-mail]>

drivers/of/irq.c

···
 
 	return of_irq_get(dev, index);
 }
+EXPORT_SYMBOL_GPL(of_irq_get_byname);
 
 /**
  * of_irq_count - Count the number of IRQs a node uses