Set access to HBB and HBI partitions to Read Only

This change removes a revert of the "Mark Read Only Partitions as
Such" change and updates the pnor makefiles to ensure HBB and HBI
partitions are marked read only at the pnor level.

Signed-off-by: Jaymes Wilks <mjwilks@us.ibm.com>
diff --git a/openpower/package/openpower-pnor/openpower-pnor.mk b/openpower/package/openpower-pnor/openpower-pnor.mk
index 04511fb..8fe7e07 100644
--- a/openpower/package/openpower-pnor/openpower-pnor.mk
+++ b/openpower/package/openpower-pnor/openpower-pnor.mk
@@ -4,7 +4,7 @@
 #
 ################################################################################
 
-OPENPOWER_PNOR_VERSION ?= f6d970c6a600a7e248fa5d604eb471db4482760b
+OPENPOWER_PNOR_VERSION ?= 491ac2632f951ba77e2220ed87b8002b01ed6fae
 OPENPOWER_PNOR_SITE ?= $(call github,open-power,pnor,$(OPENPOWER_PNOR_VERSION))
 
 OPENPOWER_PNOR_LICENSE = Apache-2.0