external: disappear iotivity log level by default
external: disappear iotivity log level by default

You do not need to use IOTIVITY_LOG_LEVEL when Iotivity is not enabled.

Change-Id: Id95b24b65d1ee30ef4d5e8642dc9d8780e10988c
Signed-off-by: Junhwan Park <7fee488b6f78fc50b291ffc7d10428788977e877@samsung.com>

JunhwanPark/TizenRT,JunhwanPark/TizenRT,JunhwanPark/TizenRT,JunhwanPark/TizenRT,JunhwanPark/TizenRT,JunhwanPark/TizenRT