op-build update August 18th

Updated hostboot version. Tested on habanero, palmetto, and firestone
HW only.
diff --git a/openpower/package/hostboot/hostboot.mk b/openpower/package/hostboot/hostboot.mk
index 431bd2e..a934119 100644
--- a/openpower/package/hostboot/hostboot.mk
+++ b/openpower/package/hostboot/hostboot.mk
@@ -4,7 +4,7 @@
 #
 ################################################################################
 
-HOSTBOOT_VERSION ?= 6e0eea061a5b8463c593a56c09accf1824fd9818
+HOSTBOOT_VERSION ?= 6ff3e00062b894a880937ce41f748e26105b579a
 HOSTBOOT_SITE ?= $(call github,open-power,hostboot,$(HOSTBOOT_VERSION))
 
 HOSTBOOT_LICENSE = Apache-2.0