esp_modem: add patch for cmux exit on A767x

Author: darkxst

patches/esp_modem_a7670_cmux_exit.diff

@@ -0,0 +1,20 @@
+diff --git a/components/esp_modem/src/esp_modem_cmux.cpp b/components/esp_modem/src/esp_modem_cmux.cpp
+index 0c480f8..4418c3d 100644
+--- a/components/esp_modem/src/esp_modem_cmux.cpp
++++ b/components/esp_modem/src/esp_modem_cmux.cpp
+@@ -206,6 +206,15 @@ bool CMux::on_header(CMuxFrame &frame)
+}
+size_t payload_offset = std::min(frame.len, 4 - frame_header_offset);
+memcpy(frame_header + frame_header_offset, frame.ptr, payload_offset);
++    if (frame_header[1] == 0xEF) {
++        dlci = 0;
++        type = frame_header[1];
++        payload_len = 0;
++        data_available(&frame.ptr[0], payload_len); // Notify DISC
++        frame.advance(payload_offset);
++        state = cmux_state::FOOTER;
++        return true;
++    }
+if ((frame_header[3] & 1) == 0) {
+      if (frame_header_offset + frame.len <= 4) {
+            frame_header_offset += frame.len;

tools/install-esp-idf.sh

@@ -41,6 +41,7 @@ if [ ! -x $idf_was_installed ] || [ ! -x $commit_predefined ]; then
 	cd $IDF_PATH
 	patch -p1 -N -i $AR_PATCHES/esp32s2_i2c_ll_master_init.diff
 	patch -p1 -N -i $AR_PATCHES/lwip_max_tcp_pcb.diff
+	patch -p1 -N -i $AR_PATCHES/esp_modem_a7670_cmux_exit.diff
 	cd -
 fi