Revert to nonos-sdk 2.2.1, new sdk-switching option in IDE menu for generic board only (#5763)

This commit allows switching SDK firmware:

nonos-sdk-pre-v3 shipped with release 2.5.0 has issues:

    * Some boards show erratic behavior (radio connection is quickly lost), with an unknown cause.
      These boards work well with previous nonos-sdk-2.2.1 firmware (#5736)

    * Overall performances seem to have decreased (#5513)

This PR restores sdk2.2.1 (as in core-2.4.2).

SDK-pre-3.0 - which has brought long awaited fixes (WiFi sleep modes) - is still available through a menu option available only with generic board.

BREAKING

    * new define `-DNONOSDK221=1` or `-DNONOSDK3V0=1`

    * for external build systems: new library directory: `tools/sdk/lib/<version>/lib`

    * PIO: variable `PIO_FRAMEWORK_ARDUINO_ESPRESSIF_SDK3` is needed for sdk-pre-v3.


Fix #5736

tools/platformio-build.py

@@ -131,6 +131,21 @@ env.Append(ASFLAGS=env.get("CCFLAGS", [])[:])
 
 flatten_cppdefines = env.Flatten(env['CPPDEFINES'])
 
+#
+# SDK
+#
+if "PIO_FRAMEWORK_ARDUINO_ESPRESSIF_SDK3" in flatten_cppdefines:
+    env.Append(
+        CPPDEFINES=[("NONOSDK3V0", 1)],
+        LIBPATH=[join(FRAMEWORK_DIR, "tools", "sdk", "lib", "NONOSDK3V0"),]
+    )
+# PIO_FRAMEWORK_ARDUINO_ESPRESSIF_SDK221 (default)
+else:
+    env.Append(
+        CPPDEFINES=[("NONOSDK221", 1)],
+        LIBPATH=[join(FRAMEWORK_DIR, "tools", "sdk", "lib", "NONOSDK221"),]
+    )
+
 #
 # lwIP
 #