meta-romulus: Bump phosphor-hwmon version

After updated to kernel dev-4.13, Romulus needs to pick latest
phosphor-hwmon to make hwmon work.

Change-Id: I7a911ad6d4dc464471e75f69963bad7e419fe198
Signed-off-by: Lei YU <mine260309@gmail.com>
diff --git a/meta-openbmc-machines/meta-openpower/meta-ibm/meta-romulus/recipes-phosphor/sensors/phosphor-hwmon%.bbappend b/meta-openbmc-machines/meta-openpower/meta-ibm/meta-romulus/recipes-phosphor/sensors/phosphor-hwmon%.bbappend
index 03b2622..d5a2ebe 100644
--- a/meta-openbmc-machines/meta-openpower/meta-ibm/meta-romulus/recipes-phosphor/sensors/phosphor-hwmon%.bbappend
+++ b/meta-openbmc-machines/meta-openpower/meta-ibm/meta-romulus/recipes-phosphor/sensors/phosphor-hwmon%.bbappend
@@ -3,7 +3,7 @@
 # Pin the revision so the patch is guaranteed to be appliable
 # TODO: Remove this when the error handling in hwmon is done:
 # https://gerrit.openbmc-project.xyz/#/c/8073/
-SRCREV = "a7e2c1e5c1e94246ae55313fc361d30b0e1a6165"
+SRCREV = "a23babd6952cb21397d6aa408a827047d1de81de"
 
 SRC_URI += " file://0001-sysfs-Return-ETIMEDOUT-instead-of-throw-exception.patch"