powerpc: add explicit OF includes

When removing prom.h include by of.h, several OF headers will no longer
be implicitly included. Add explicit includes of of_*.h as needed.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Acked-by: Grant Likely <grant.likely@linaro.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Anatolij Gustschin <agust@denx.de>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Olof Johansson <olof@lixom.net>
Cc: linuxppc-dev@lists.ozlabs.org

arch/powerpc/platforms/86xx/pic.c

@@ -10,6 +10,7 @@
 #include <linux/stddef.h>
 #include <linux/kernel.h>
 #include <linux/interrupt.h>
+#include <linux/of_irq.h>
 #include <linux/of_platform.h>
 
 #include <asm/mpic.h>