esp enc -> subdir

esp_encrypted_img/project_include.cmake

@@ -0,0 +1,18 @@
+set(ESP_IMG_GEN_TOOL_PATH ${CMAKE_CURRENT_LIST_DIR}/tools/esp_enc_img_gen.py)
+
+function(create_esp_enc_img input_file rsa_key_file output_file app)
+    cmake_parse_arguments(arg "${options}" "" "${multi}" "${ARGN}")
+    idf_build_get_property(python PYTHON)
+
+    add_custom_command(OUTPUT ${output_file}
+        POST_BUILD
+        COMMAND ${python} ${ESP_IMG_GEN_TOOL_PATH} encrypt
+            ${input_file}
+            ${rsa_key_file} ${output_file}
+        DEPENDS gen_project_binary
+        COMMENT "Generating pre-encrypted binary"
+        VERBATIM
+    )
+    add_custom_target(encrypt_bin_target DEPENDS ${output_file})
+    add_dependencies(${app} encrypt_bin_target)
+endfunction()