meta-toolchain-osmo: Include the builddate in the toolchain

When updating libosmocore and other libraries we would like to
know which toolchain version is used. Add the datetime to the
filename.
diff --git a/recipes-osmocom/meta/meta-toolchain-osmo.bb b/recipes-osmocom/meta/meta-toolchain-osmo.bb
index 336e95f..3d4a00a 100644
--- a/recipes-osmocom/meta/meta-toolchain-osmo.bb
+++ b/recipes-osmocom/meta/meta-toolchain-osmo.bb
@@ -1,6 +1,6 @@
 #TOOLCHAIN_TARGET_OSMOTASK ?= "task-core-standalone-osmo-sdk-target task-core-standalone-osmo-sdk-target-dbg"
 TOOLCHAIN_TARGET_OSMOTASK ?= "task-core-standalone-osmo-sdk-target"
 TOOLCHAIN_TARGET_TASK = "${TOOLCHAIN_TARGET_OSMOTASK}"
-TOOLCHAIN_OUTPUTNAME = "${SDK_NAME}-toolchain-osmo-${DISTRO_VERSION}"
+TOOLCHAIN_OUTPUTNAME = "${SDK_NAME}-toolchain-osmo-${DISTRO_VERSION}-${DATETIME}"
 PROVIDES = "meta-toolchain-sdk"
 require recipes-core/meta/meta-toolchain.bb