Dynamic cfg: MISRA fixes ...

Change-Id: I1d85b76af002b8b672fcaeca94939b7420bc8243
Signed-off-by: Soby Mathew <soby.mathew@arm.com>

Dynamic cfg: Introduce fdt wrappers ...

Change-Id: I9b1cdaf2430a1998a69aa366ea1461224a3d43dc
Co-Authoured-by: Jeenu Viswambharan <Jeenu.Viswambharan@arm.com>
Signed-off-by: Soby Mathew <soby.mathew@arm.com>