op-build update Oct 20th

Updated versions: hostboot, firestone-xml, garrison-xml

Tested on: palmetto, habanero, and firestone (boot to Petitboot only)
diff --git a/openpower/package/garrison-xml/garrison.mk b/openpower/package/garrison-xml/garrison.mk
index 48e873f..9b96606 100644
--- a/openpower/package/garrison-xml/garrison.mk
+++ b/openpower/package/garrison-xml/garrison.mk
@@ -4,7 +4,7 @@
 #
 ################################################################################
 
-GARRISON_XML_VERSION ?= 7f55731b2777f2a1f52dabfb03b7512cc0d365f8
+GARRISON_XML_VERSION ?= 884bf2466dcc1b63baf92758e50fcc8e2ec551c5
 GARRISON_XML_SITE ?= $(call github,open-power,garrison-xml,$(GARRISON_XML_VERSION))
 
 GARRISON_XML_LICENSE = Apache-2.0