xive: Don't try setting the reserved ACK# field in VPs

That doesn't work, the HW doesn't implement it in the cache
watch facility anyway.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>

hw/xive.c

@@ -882,11 +882,8 @@ static void xive_init_default_vp(struct xive_vp *vp,
 {
 	memset(vp, 0, sizeof(struct xive_vp));
 
-	/* Stash the EQ base in the pressure relief interrupt field
-	 * and set the ACK# to 0xff to disable pressure relief interrupts
-	 */
+	/* Stash the EQ base in the pressure relief interrupt field */
 	vp->w1 = (eq_blk << 28) | eq_idx;
-	vp->w5 = 0xff000000;
 	vp->w0 = VP_W0_VALID;
 }