mtmd : fix mtmd ios build (ggml-org#15579)

Author: fidoriel

tools/mtmd/CMakeLists.txt

@@ -55,6 +55,8 @@ add_executable(llama-qwen2vl-cli  deprecation-warning.cpp)
 set(TARGET llama-mtmd-cli)
 add_executable         (${TARGET} mtmd-cli.cpp)
 set_target_properties  (${TARGET} PROPERTIES OUTPUT_NAME llama-mtmd-cli)
-install                (TARGETS ${TARGET} RUNTIME)
+if(NOT CMAKE_SYSTEM_NAME STREQUAL "iOS")
+    install(TARGETS ${TARGET} RUNTIME)
+endif()
 target_link_libraries  (${TARGET} PRIVATE common mtmd Threads::Threads)
 target_compile_features(${TARGET} PRIVATE cxx_std_17)