recipes-test: Add diag recipe
recipes-test: Add diag recipe

DIAG implements routing of diagnostics related messages between host
and various subsystems.

Signed-off-by: Aníbal Limón <4676e39632f2bd46f30a0e877949547c228033d4@linaro.org>
(cherry picked from commit 8911dc8d442f12b272e845a64c95a843f58b03db)

ndechesne/meta-qcom,ndechesne/meta-qcom,ndechesne/meta-qualcomm,ndechesne/meta-qcom