Build tinyusb lib only when it's explicitly enabled

Resolve platformio#474

Author: valeros

builder/frameworks/espidf.py

@@ -1281,7 +1281,7 @@ def _skip_prj_source_files(node):
 # in File-API hence it's not present in components map. As a workaround we can build
 # the lib using project build environment with additional flags from CMakeLists.txt
 if (
-    idf_variant.startswith("esp32s2")
+    sdk_config.get("USB_ENABLED", False)
     and "__idf_tinyusb" not in framework_components_map
 ):
     build_tinyusb_lib(env)

examples/espidf-http-request/platformio.ini

@@ -21,5 +21,5 @@ board = nano32
 [env:espea32]
 board = espea32
 
-[env:esp320]
-board = esp320
+[env:esp32-s2-saola-1]
+board = esp32-s2-saola-1