Make on static library SIMU, drop SIMU_COMMON

Almost all targets used both SIMU and SIMU_COMMON. So instead of
linking one in the other, this commit merges both libraries into a
common SIMU lib.  Further, we never load SIMU dynamically -- hence
make it a static library.

Also, this commit cleans up CMakeLists.txt to prevent multiple
compilations of taus.c

docker/Dockerfile.lteUE.rhel8.2

@@ -70,7 +70,6 @@ COPY --from=lte-ue-build \
     /oai-ran/cmake_targets/ran_build/build/liboai_usrpdevif.so \
     /oai-ran/cmake_targets/ran_build/build/libcoding.so \
     /oai-ran/cmake_targets/ran_build/build/libparams_libconfig.so \
-    /oai-ran/cmake_targets/ran_build/build/libSIMU.so \
     /oai-ran/cmake_targets/ran_build/build/libdfts.so \
     /oai-ran/cmake_targets/ran_build/build/libtelnetsrv.so \
     /usr/local/lib/

docker/Dockerfile.lteUE.ubuntu18

@@ -76,7 +76,6 @@ COPY --from=lte-ue-build \
     /oai-ran/cmake_targets/ran_build/build/liboai_usrpdevif.so \
     /oai-ran/cmake_targets/ran_build/build/libcoding.so \
     /oai-ran/cmake_targets/ran_build/build/libparams_libconfig.so \
-    /oai-ran/cmake_targets/ran_build/build/libSIMU.so \
     /oai-ran/cmake_targets/ran_build/build/libdfts.so \
     /oai-ran/cmake_targets/ran_build/build/libtelnetsrv.so \
     /usr/local/lib/

docker/Dockerfile.phySim.rhel8.2

@@ -89,7 +89,6 @@ COPY --from=phy-sim-build \
     /lib64/libxslt.so.1 \
     /usr/lib64/libasan.so.5 \
     /oai-ran/cmake_targets/ran_build/build/libdfts.so \
-    /oai-ran/cmake_targets/ran_build/build/libSIMU.so \
     /oai-ran/cmake_targets/ran_build/build/libldpc.so \
     /oai-ran/cmake_targets/ran_build/build/libldpc_orig.so \
     /usr/local/lib/