Add the trusted boot firmware configuration information into
the BL2 device tree. It enabled the authentication.
MBEDTLS heap is not defined, it will use the hard coded one.

Signed-off-by: Lionel Debieve <lionel.debieve@st.com>
Signed-off-by: Nicolas Toromanoff <nicolas.toromanoff@st.com>
Change-Id: I47181d179b814dc512dc527ae54a5a19a126f1c5
Reviewed-on: https://gerrit.st.com/c/mpu/oe/st/tf-a/+/184833


Reviewed-by: CITOOLS <smet-aci-reviews@lists.codex.cro.st.com>
Reviewed-by: CIBUILD <smet-aci-builds@lists.codex.cro.st.com>
Reviewed-by: Yann GAUTIER <yann.gautier@st.com>