[POWERPC] Make the hvc_console output buffer size settable

So the iSeries console will be faster since it can send up to 200 bytes at
a time to the Hypervisor.  This only affects the tty part of the console,
the console writes are still in 16 byte lots.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
diff --git a/drivers/char/hvc_vio.c b/drivers/char/hvc_vio.c
index 9add81ce..651e5d2 100644
--- a/drivers/char/hvc_vio.c
+++ b/drivers/char/hvc_vio.c
@@ -90,7 +90,8 @@
 	if (!vdev || !id)
 		return -EPERM;
 
-	hp = hvc_alloc(vdev->unit_address, vdev->irq, &hvc_get_put_ops);
+	hp = hvc_alloc(vdev->unit_address, vdev->irq, &hvc_get_put_ops,
+			MAX_VIO_PUT_CHARS);
 	if (IS_ERR(hp))
 		return PTR_ERR(hp);
 	dev_set_drvdata(&vdev->dev, hp);