pflash: bump version to v5.9.4

Bumping to pick up pflash fix
lists.ozlabs.org/pipermail/skiboot/2017-November/009601.html

Change-Id: I23eb1a32c7fde316e1d125eccdced397fb12adab
Signed-off-by: Gunnar Mills <gmills@us.ibm.com>
diff --git a/meta-openbmc-machines/meta-openpower/common/recipes-bsp/skiboot/skiboot.inc b/meta-openbmc-machines/meta-openpower/common/recipes-bsp/skiboot/skiboot.inc
index ea4adb9..01a2461 100644
--- a/meta-openbmc-machines/meta-openpower/common/recipes-bsp/skiboot/skiboot.inc
+++ b/meta-openbmc-machines/meta-openpower/common/recipes-bsp/skiboot/skiboot.inc
@@ -8,8 +8,8 @@
 
 LIC_FILES_CHKSUM = "file://${S}/LICENCE;md5=3b83ef96387f14655fc854ddc3c6bd57"
 
-SRCREV = "e0ee24c27a172bcf482f6f2bc905e6211c134bcc"
-PV = "v5.9"
+SRCREV = "1a1a2bd43829dc49c63fda07c569fbfcb73353a5"
+PV = "v5.9.4"
 
 S = "${WORKDIR}/git"