modules: update OpenWrt

ef686b7292 uqmi: bump to latest git HEAD
3dc740257b uqmi: inherit firewall zone membership to virtual sub interfaces
a2c22b8776 uqmi: fix PIN_STATUS_FAILED error with MC7455 WCDMA/LTE modem
d5ff0897cb kernel: bump 4.14 to 4.14.131
18266fc6c0 kernel: bump 4.9 to 4.9.184

Compile-tested: mpc85xx-generic, ramips-mt7621
Runtime-tested: mpc85xx-generic (TP-Link WDR4900 v1), ramips-mt7621 (D-Link DIR-860L B1)

modules

@@ -2,7 +2,7 @@ GLUON_FEEDS='packages routing luci gluon'
 
 OPENWRT_REPO=https://git.openwrt.org/openwrt/openwrt.git
 OPENWRT_BRANCH=openwrt-18.06
-OPENWRT_COMMIT=5e771160b81bfec760a5f7f114cc5dc41ff595e6
+OPENWRT_COMMIT=ef686b72923792d6db852a752a07649fe38eca6b
 
 PACKAGES_PACKAGES_REPO=https://github.com/openwrt/packages.git
 PACKAGES_PACKAGES_BRANCH=openwrt-18.06