components/bt: Move function in interrupt into IRAM

1. Move function in interrupt into IRAM
2. Delete unused code, saving 240B DRAM and some code size

diff --git a/components/bt/lib b/components/bt/lib
index 03909fd446dfc15dea00357329ab73e788e77e11..cc76161dfac47ca03aa4ed60e610b5c5811f43ff 160000 (submodule)
--- a/components/bt/lib
+++ b/components/bt/lib
@@ -1 +1 @@
-Subproject commit 03909fd446dfc15dea00357329ab73e788e77e11
+Subproject commit cc76161dfac47ca03aa4ed60e610b5c5811f43ff