openpower-libhei: srcrev bump a27b584cb2..e4ad4e3c08

Caleb Palmer (1):
      Add support in the isolator to perform write operations on a signature

Change-Id: I1ed456cee1b4c76c67247db12c0b6094b73d9988
Signed-off-by: Andrew Geissler <openbmcbump-github@yahoo.com>
diff --git a/meta-openpower/recipes-phosphor/logging/openpower-libhei-rev.inc b/meta-openpower/recipes-phosphor/logging/openpower-libhei-rev.inc
index 1a8e711..234b86c 100644
--- a/meta-openpower/recipes-phosphor/logging/openpower-libhei-rev.inc
+++ b/meta-openpower/recipes-phosphor/logging/openpower-libhei-rev.inc
@@ -2,5 +2,5 @@
 PV = "0.1+git${SRCPV}"
 
 SRC_URI = "git://github.com/openbmc/openpower-libhei;branch=master;protocol=https"
-SRCREV = "a27b584cb2153070872b2a9c3f16020a4cd348f3"
+SRCREV = "e4ad4e3c08992c7d697ef0b8416c3656a81c4c79"