powerpc: Pass a valid token to rtas_call() in phyp-dump code

ibm_configure_kernel_dump is passed as the token to rtas_call() is
never initialised.  This sets it to something sane.
Signed-off-by: Tony Breeds <tony@bakeyournoodle.com>
Acked-by: Nathan Lynch <ntl@pobox.com>
Acked-by: Manish Ahuja <mahujam@gmail.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/platforms/pseries/phyp_dump.c

@@ -414,6 +414,8 @@ static int __init phyp_dump_setup(void)
 		of_node_put(rtas);
 	}
 
+	ibm_configure_kernel_dump = rtas_token("ibm,configure-kernel-dump");
+
 	print_dump_header(dump_header);
 	dump_area_length = init_dump_header(&phdr);
 	/* align down */