Add SIERRA flag for tinyDTLS component
Add SIERRA flag for tinyDTLS component

Resolves: LE-10716 LE-10774
Related: LE-10754
Change-Id: Ib67721cf9749a6172048f16b93755e8ba0785442

legatoproject/legato-af,legatoproject/legato-af,legatoproject/legato-af,legatoproject/legato-af,legatoproject/legato-af,legatoproject/legato-af,legatoproject/legato-af,legatoproject/legato-af,legatoproject/legato-af