misc: Modernize and call it packagegroup-

The notion of task- has been deprecated a long time ago. Call
it packagegroup now and for "packagegroup-osmocom" provide the
compability. This has not been compile tested.

The edison build will require a bbappend to provide packagegroup
now but I will do this once I need to build for Edison again.
diff --git a/recipes-osmocom/meta/meta-toolchain-osmo.bb b/recipes-osmocom/meta/meta-toolchain-osmo.bb
index 566ec26..6755fb6 100644
--- a/recipes-osmocom/meta/meta-toolchain-osmo.bb
+++ b/recipes-osmocom/meta/meta-toolchain-osmo.bb
@@ -1,5 +1,4 @@
-#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_OSMOTASK ?= "packagegroup-core-standalone-osmo-sdk-target"
 TOOLCHAIN_TARGET_TASK = "${TOOLCHAIN_TARGET_OSMOTASK}"
 TOOLCHAIN_OUTPUT_BASENAME = "${SDK_NAME}-toolchain-osmo-${DISTRO_VERSION}"
 TOOLCHAIN_OUTPUTNAME = "${TOOLCHAIN_OUTPUT_BASENAME}-${DATETIME}"