Add PROJECT_SOURCE_DIR for bootloader to enable bootloader_components build (platformio#1460)

Author: DamienEspitallier

builder/frameworks/espidf.py

@@ -879,6 +879,7 @@ def build_bootloader(sdk_config):
             "-DPYTHON=" + get_python_exe(),
             "-DIDF_PATH=" + FRAMEWORK_DIR,
             "-DSDKCONFIG=" + SDKCONFIG_PATH,
+            "-DPROJECT_SOURCE_DIR=" + PROJECT_DIR,
             "-DLEGACY_INCLUDE_COMMON_HEADERS=",
             "-DEXTRA_COMPONENT_DIRS="
             + os.path.join(FRAMEWORK_DIR, "components", "bootloader"),