CMake in turbulence library mode

[qingli411]

Building only the turbulence library using cmake with -DGOTM_BUILD_LIBRARIES_ONLY=true fails in the v6.0.0 release (and the master branch as well) due to a missing dependency on input when building airsea. I don't think airsea is needed in the turbulence library, right? So moving the following line after the check on GOTM_BUILD_LIBRARIES_ONLY seems to fix this. I didn't check if this change breaks the building with FABM etc though... @bolding @jornbr

code/src/CMakeLists.txt

Line 52 in 7b8078b

add_subdirectory(${CMAKE_CURRENT_LIST_DIR}/airsea airsea)