build: change the build order of apps
build: change the build order of apps

This patch changes the build order of apps in order to build apps
directories later than external directories.

If apps/examples/iotivity_apps are built earlier than external/
iotivity, build error can occur because apps/examples/iotivity_apps
refers to the header file which is auto-generated by external/iotivity.

Change-Id: I94d3025c15aba2fc18a60ff4169ce00c8c429257
Signed-off-by: Wonsang Ryou <bc48fb2bc21aa3a9d3ccd13729d9fc0f5ca913dd@samsung.com>

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