powerpc: Consolidate mpic_alloc() OF address translation

Instead of using the open-coded "reg" property lookup and address
translation in mpic_alloc(), directly call of_address_to_resource().
This includes various workarounds for special cases which the naive
of_address_translate() does not.

Afterwards it is possible to remove the copiously copy-pasted calls to
of_address_translate() from the 85xx/86xx/powermac platforms.

Signed-off-by: Kyle Moffett <Kyle.D.Moffett@boeing.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/platforms/85xx/mpc85xx_rdb.c b/arch/powerpc/platforms/85xx/mpc85xx_rdb.c
index b1ca429..2b299eba 100644
--- a/arch/powerpc/platforms/85xx/mpc85xx_rdb.c
+++ b/arch/powerpc/platforms/85xx/mpc85xx_rdb.c
@@ -45,7 +45,6 @@
 void __init mpc85xx_rdb_pic_init(void)
 {
 	struct mpic *mpic;
-	struct resource r;
 	struct device_node *np;
 	unsigned long root = of_get_flat_dt_root();
 
@@ -55,20 +54,14 @@
 		return;
 	}
 
-	if (of_address_to_resource(np, 0, &r)) {
-		printk(KERN_ERR "Failed to map mpic register space\n");
-		of_node_put(np);
-		return;
-	}
-
 	if (of_flat_dt_is_compatible(root, "fsl,MPC85XXRDB-CAMP")) {
-		mpic = mpic_alloc(np, r.start,
+		mpic = mpic_alloc(np, 0,
 			MPIC_PRIMARY |
 			MPIC_BIG_ENDIAN | MPIC_BROKEN_FRR_NIRQS |
 			MPIC_SINGLE_DEST_CPU,
 			0, 256, " OpenPIC  ");
 	} else {
-		mpic = mpic_alloc(np, r.start,
+		mpic = mpic_alloc(np, 0,
 		  MPIC_PRIMARY | MPIC_WANTS_RESET |
 		  MPIC_BIG_ENDIAN | MPIC_BROKEN_FRR_NIRQS |
 		  MPIC_SINGLE_DEST_CPU,