Add a note to the "Run Celadon as the User VM" tutorial to indicate a serial
port connection to the platform (or change of the default config) may be needed
if the user uses a scenario other than SDC (the default one in the doc).
Tracked-On: #4554
Signed-off-by: Geoffroy Van Cutsem <geoffroy.vancutsem@intel.com>
a69a5608da