Pick up Skiboot Change for Checkstop Analysis At Runtime

This commit picks up the following skiboot change for checkstop
analysis at runtime: http://patchwork.ozlabs.org/patch/464376/
diff --git a/openpower/package/skiboot/skiboot-0002-prd-Only-alter-host-presentation-bits-of-IPOLL-mask.patch b/openpower/package/skiboot/skiboot-0002-prd-Only-alter-host-presentation-bits-of-IPOLL-mask.patch
new file mode 100644
index 0000000..68a4cbd
--- /dev/null
+++ b/openpower/package/skiboot/skiboot-0002-prd-Only-alter-host-presentation-bits-of-IPOLL-mask.patch
@@ -0,0 +1,47 @@
+diff --git a/hw/prd.c b/hw/prd.c
+index e65ae57..4862213 100644
+--- a/hw/prd.c
++++ b/hw/prd.c
+@@ -226,12 +226,13 @@ static int ipoll_record_and_mask_pending(uint32_t proc)
+ 
+ 	lock(&ipoll_lock);
+ 	rc = xscom_read(proc, PRD_IPOLL_REG_STATUS, &status);
++	status &= PRD_IPOLL_MASK;
+ 	if (!rc)
+ 		__ipoll_update_mask(proc, true, status);
+ 	unlock(&ipoll_lock);
+ 
+ 	if (!rc)
+-		ipoll_status[proc] |= (status & PRD_IPOLL_MASK);
++		ipoll_status[proc] |= status;
+ 
+ 	return rc;
+ }
+@@ -284,7 +285,8 @@ static int prd_msg_handle_init(struct opal_prd_msg *msg)
+ 
+ 	lock(&ipoll_lock);
+ 	for_each_chip(chip) {
+-		__ipoll_update_mask(chip->id, false, msg->init.ipoll);
++		__ipoll_update_mask(chip->id, false,
++			msg->init.ipoll & PRD_IPOLL_MASK);
+ 	}
+ 	unlock(&ipoll_lock);
+ 
+@@ -309,7 +311,7 @@ static int prd_msg_handle_fini(void)
+ 
+ 	lock(&ipoll_lock);
+ 	for_each_chip(chip) {
+-		__ipoll_update_mask(chip->id, true, -1ul);
++		__ipoll_update_mask(chip->id, true, PRD_IPOLL_MASK);
+ 	}
+ 	unlock(&ipoll_lock);
+ 
+@@ -345,7 +347,7 @@ void prd_init(void)
+ 	/* mask everything */
+ 	lock(&ipoll_lock);
+ 	for_each_chip(chip) {
+-		__ipoll_update_mask(chip->id, true, -1ul);
++		__ipoll_update_mask(chip->id, true, PRD_IPOLL_MASK);
+ 	}
+ 	unlock(&ipoll_lock);
+