fix(mediatek): switch console to runtime state before leaving BL31

We should switch console to runtime state. If we don't do this, the
state will keep boot state even we exit from BL31.

Signed-off-by: Bo-Chen Chen <rex-bc.chen@mediatek.com>
Change-Id: Id2269ccf2fdc22e0fa088c3c0365836730172233
1 file changed