firestone: Bump xml version

With this we can actually build a Firestone PNOR.

Signed-off-by: Samuel Mendoza-Jonas <sam@mendozajonas.com>
diff --git a/openpower/configs/firestone_defconfig b/openpower/configs/firestone_defconfig
index 3b43d0b..2c9290a 100644
--- a/openpower/configs/firestone_defconfig
+++ b/openpower/configs/firestone_defconfig
@@ -42,7 +42,7 @@
 BR2_OPENPOWER_POWER8=y
 BR2_HOSTBOOT_P8_CONFIG_FILE="firestone.config"
 BR2_OPENPOWER_MACHINE_XML_GITHUB_PROJECT_VALUE="firestone-xml"
-BR2_OPENPOWER_MACHINE_XML_VERSION="2494a430656504d014780000adbc2c2e7cfc54ab"
+BR2_OPENPOWER_MACHINE_XML_VERSION="9df12d2653f2fbcae043d0e8effadb9aa5b84694"
 BR2_OPENPOWER_MACHINE_XML_FILENAME="firestone.xml"
 BR2_OPENPOWER_SYSTEM_XML_FILENAME="FIRESTONE_hb.system.xml"
 BR2_OPENPOWER_MRW_XML_FILENAME="FIRESTONE_hb.mrw.xml"