fsp2: move to 4.17.18

Bump the linux kernel version to 4.17.18 which includes
fix for the secuirity vulnerability in #3359.

(From meta-ibm rev: 122f4e781fbcd81e83a18723d47af9c3d492c9a7)

Change-Id: I37cb893989cdc924f7905bb915d9111e4ac6631d
Signed-off-by: Ivan Mikhaylov <ivan@de.ibm.com>
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/meta-ibm/meta-fsp2/recipes-kernel/linux/linux-fsp2.inc b/meta-ibm/meta-fsp2/recipes-kernel/linux/linux-fsp2.inc
index 0f65dfe..23ecc45 100644
--- a/meta-ibm/meta-fsp2/recipes-kernel/linux/linux-fsp2.inc
+++ b/meta-ibm/meta-fsp2/recipes-kernel/linux/linux-fsp2.inc
@@ -4,7 +4,7 @@
 
 KCONFIG_MODE="--alldefconfig"
 
-KSRC ?= "git://github.com/openbmc/linux;protocol=git;branch=dev-4.13"
+KSRC ?= "git://github.com/openbmc/linux;protocol=git;branch=dev-4.17"
 SRC_URI = "${KSRC}"
 
 LINUX_VERSION_EXTENSION ?= "-${SRCREV}"