feat(st-regulator): add support for regulator-always-on

Add support for regulator-always-on at BL2 level as it was supported
before using the regulator framework.

Signed-off-by: Pascal Paillet <p.paillet@st.com>
Change-Id: Idb2f4ddc2fdd4e0d31fb33da87c84618aa2e5135
1 file changed