of: remove unnecessary prom.h includes

Remove unnecessary prom.h includes in preparation to make prom.h optional.
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Acked-by: Grant Likely <grant.likely@linaro.org>

drivers/of/of_pci_irq.c

@@ -2,7 +2,6 @@
 #include <linux/of_pci.h>
 #include <linux/of_irq.h>
 #include <linux/export.h>
-#include <asm/prom.h>
 
 /**
  * of_irq_map_pci - Resolve the interrupt for a PCI device

drivers/of/pdt.c

@@ -22,7 +22,6 @@
 #include <linux/slab.h>
 #include <linux/of.h>
 #include <linux/of_pdt.h>
-#include <asm/prom.h>
 
 static struct of_pdt_ops *of_pdt_prom_ops __initdata;