esp32: update libphy.a to v3960

Update libphy.a to v3960:
1. Decrease  phy_init time from 900us to 347us in sleep wakeup
2. Fix RX STBC initialization
3. Modify set_chan function to fix interrupt watchdog issue

diff --git a/components/esp32/lib b/components/esp32/lib
index 828e45773609055cdd396cd7556aa142faf30003..62e3f71f35b228f354e6fd2ee8c743bacb55016e 160000 (submodule)
--- a/components/esp32/lib
+++ b/components/esp32/lib
@@ -1 +1 @@
-Subproject commit 828e45773609055cdd396cd7556aa142faf30003
+Subproject commit 62e3f71f35b228f354e6fd2ee8c743bacb55016e