cmake: revert the change which breaks cmake build with llvm + openmp

cmake/BuildMisc.cmake

@@ -34,7 +34,6 @@ macro(libmisc_build)
     add_library(misc STATIC ${misc_src})
 
     if (HAVE_OPENMP)
-        target_compile_options(misc PRIVATE "-fopenmp")
         if(BUILD_STATIC)
             set(GOMP_LIBRARY libgomp.a)
         else()

cmake/compiler.cmake

@@ -280,6 +280,11 @@ macro(enable_tnt_compile_flags)
     endif()
 endmacro(enable_tnt_compile_flags)
 
+if (HAVE_OPENMP)
+    add_compile_flags("C;CXX" "-fopenmp")
+endif()
+
+
 if (CMAKE_COMPILER_IS_CLANG OR CMAKE_COMPILER_IS_GNUCC)
     set(HAVE_BUILTIN_CTZ 1)
     set(HAVE_BUILTIN_CTZLL 1)