minnowboard: use console/serial peripheral

Use console/serial peripheral.

BUG=none
Change-Id: I9f89ee6a70bf7775920e59298393b26c7c95990f
Tracked-On: https://jira01.devtools.intel.com/browse/BP-285
Signed-off-by: Bruce Beare <bruce.j.beare@intel.com>
Signed-off-by: Viorel Suman <viorel.suman@intel.com>