Fix some wifi lib bugs

1. add adc2 coexistence

2. change NOW() to WDEV_NOW()

3. call ets_timer_done() before calling ets_timer_setfn()

4. fix the bug that api lock is not unlocked when call esp_wifi_stop()
   twice

5. more hmac tx buffer limit from 32 to 64.

diff --git a/components/esp32/lib b/components/esp32/lib
index 3fe7f3a0a5f570b22182063fcc6d7dad6875dfbd..a3c8f349fe3c9e5be6cf74b813a1dc505fe38dc1 160000 (submodule)
--- a/components/esp32/lib
+++ b/components/esp32/lib
@@ -1 +1 @@
-Subproject commit 3fe7f3a0a5f570b22182063fcc6d7dad6875dfbd
+Subproject commit a3c8f349fe3c9e5be6cf74b813a1dc505fe38dc1