When we parse the param from BL2, we try to parse it as a FDT and then,
if that fails, as aux params. However, we don't sufficiently distinguish
between failure modes in the first step: specifically, if we are given
an FDT with good magic that we can't parse for some other reason (e.g.
not enough space in our buffer), we still attempt to parse it as aux
params even though that's guaranteed to fatal. Instead, we should either
fail with a more descriptive message or continue to boot without parsing
the FDT.

This patch takes the latter approach, since all we currently get from
the FDT is non-critical UART params.

Signed-off-by: Thomas Hebb <tommyhebb@gmail.com>
Change-Id: I1e98f1fcda4f78e6b45e86956288bafe58b113e4