init: add support for DT

This patch changes default behavior when looking
for machine name because current way will show
the same name for all OMAP4 machines if they are
DT-enabled. Use different way instead

Change-Id: I7b3b9980fd4a746626389ec431833fe1fd27c530
Signed-off-by: Ruslan Bilovol <ruslan.bilovol@ti.com>