capp-ucode: update to fix build fail on RHEL.

Signed-off-by: Patrick Williams <iawillia@us.ibm.com>
diff --git a/openpower/package/capp-ucode/capp-ucode.mk b/openpower/package/capp-ucode/capp-ucode.mk
index a295f60..88a9020 100644
--- a/openpower/package/capp-ucode/capp-ucode.mk
+++ b/openpower/package/capp-ucode/capp-ucode.mk
@@ -3,7 +3,7 @@
 # capp-ucode.mk
 #
 ################################################################################
-CAPP_UCODE_VERSION ?= e5167a6f534ea3bdc2faef80dc37ee806a3f2eb1
+CAPP_UCODE_VERSION ?= d4b26834dd674b83971d00a8c0952fa5830c8f6a
 CAPP_UCODE_SITE ?= $(call github,open-power,capp-ucode,$(CAPP_UCODE_VERSION))
 PETITBOOT_LICENSE = Apache-2.0