of/irq: Fix pSeries boot failure

of_irq_parse_raw() needs to return the correct interrupt controller
node when an interrupt-map property doesn't exist.

It allows of_irq_parse_raw() to return the node pointer of the interrupt
controller, rather than the parent bus. This allows ics_rtas_host_match()
to detect that the controller is a legacy 8259 and avoid using xics.
This avoids an RTAS assertion/crash during early kernel bootstrapping.

Signed-off-by: Jeremy Linton <lintonrjeremy@gmail.com>
Reviewed-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Grant Likely <grant.likely@linaro.org>

drivers/of/irq.c

@@ -252,8 +252,6 @@ int of_irq_parse_raw(const __be32 *addr, struct of_phandle_args *out_irq)
 		 * Successfully parsed an interrrupt-map translation; copy new
 		 * interrupt specifier into the out_irq structure
 		 */
-		out_irq->np = newpar;
-
 		match_array = imap - newaddrsize - newintsize;
 		for (i = 0; i < newintsize; i++)
 			out_irq->args[i] = be32_to_cpup(imap - newintsize + i);
@@ -262,6 +260,7 @@ int of_irq_parse_raw(const __be32 *addr, struct of_phandle_args *out_irq)
 
 	skiplevel:
 		/* Iterate again with new parent */
+		out_irq->np = newpar;
 		pr_debug(" -> new parent: %s\n", of_node_full_name(newpar));
 		of_node_put(ipar);
 		ipar = newpar;