[POWERPC] clean up pseries hcall interfaces

Our pseries hcall interfaces are out of control:

	plpar_hcall_norets
	plpar_hcall
	plpar_hcall_8arg_2ret
	plpar_hcall_4out
	plpar_hcall_7arg_7ret
	plpar_hcall_9arg_9ret

Create 3 interfaces to cover all cases:

	plpar_hcall_norets:	7 arguments no returns
	plpar_hcall:		6 arguments 4 returns
	plpar_hcall9:		9 arguments 9 returns

There are only 2 cases in the kernel that need plpar_hcall9, hopefully
we can keep it that way.

Pass in a buffer to stash return parameters so we avoid the &dummy1,
&dummy2 madness.

Signed-off-by: Anton Blanchard <anton@samba.org>
--
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c
index 10e10be..14353b8 100644
--- a/arch/powerpc/kernel/rtas.c
+++ b/arch/powerpc/kernel/rtas.c
@@ -668,15 +668,14 @@
 	int i;
 	long state;
 	long rc;
-	unsigned long dummy;
-
+	unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
 	struct rtas_suspend_me_data data;
 
 	/* Make sure the state is valid */
-	rc = plpar_hcall(H_VASI_STATE,
-			 ((u64)args->args[0] << 32) | args->args[1],
-			 0, 0, 0,
-			 &state, &dummy, &dummy);
+	rc = plpar_hcall(H_VASI_STATE, retbuf,
+			 ((u64)args->args[0] << 32) | args->args[1]);
+
+	state = retbuf[0];
 
 	if (rc) {
 		printk(KERN_ERR "rtas_ibm_suspend_me: vasi_state returned %ld\n",rc);