feat(plat/st): create new helper for DT access

dt_match_instance_by_compatible() gives the DT node offset in DT
that matches both compatible and the peripheral instance address.

Change-Id: Ia85f4f4aa8fe8efd4df310d765e7586e67aa34c2
Signed-off-by: Yann Gautier <yann.gautier@st.com>
2 files changed