of: fix sparse warnings in fdt, irq, reserved mem, and resolver code

sparse generates the following warnings in drivers/of/:

../drivers/of/fdt.c:63:36: warning: cast to restricted __be32
../drivers/of/fdt.c:68:33: warning: cast to restricted __be32
../drivers/of/irq.c:105:88: warning: incorrect type in initializer (different base types)
../drivers/of/irq.c:105:88:    expected restricted __be32
../drivers/of/irq.c:105:88:    got int
../drivers/of/irq.c:526:35: warning: incorrect type in assignment (different modifiers)
../drivers/of/irq.c:526:35:    expected int ( *const [usertype] irq_init_cb )( ... )
../drivers/of/irq.c:526:35:    got void const *const data
../drivers/of/of_reserved_mem.c:200:50: warning: incorrect type in initializer (different modifiers)
../drivers/of/of_reserved_mem.c:200:50:    expected int ( *[usertype] initfn )( ... )
../drivers/of/of_reserved_mem.c:200:50:    got void const *const data
../drivers/of/resolver.c:95:42: warning: incorrect type in assignment (different base types)
../drivers/of/resolver.c:95:42:    expected unsigned int [unsigned] [usertype] <noident>
../drivers/of/resolver.c:95:42:    got restricted __be32 [usertype] <noident>

All these are harmless type mismatches fixed by adjusting the types.

Signed-off-by: Rob Herring <robh@kernel.org>
diff --git a/include/linux/of_irq.h b/include/linux/of_irq.h
index 1e0deb8..ec6b11de 100644
--- a/include/linux/of_irq.h
+++ b/include/linux/of_irq.h
@@ -8,7 +8,7 @@
 #include <linux/ioport.h>
 #include <linux/of.h>
 
-typedef int (*of_irq_init_cb_t)(struct device_node *, struct device_node *);
+typedef int const (*of_irq_init_cb_t)(struct device_node *, struct device_node *);
 
 /*
  * Workarounds only applied to 32bit powermac machines