axtls: update to bddda2a0

- update ssl_client_new signature
- add max fragment length negotiation support (hardcoded to 4096 bytes)
- build axtls with -f{function,data}-sections, ~1k less DRAM usage,
  ~3k less flash
- strip prefix from build paths in debug symbols

tools/sdk/ld/eagle.app.v6.common.ld

@@ -165,6 +165,7 @@ SECTIONS
     *libstdc++.a:(.literal .text .literal.* .text.*)
     *liblwip_gcc.a:(.literal .text .literal.* .text.*)
     *liblwip_src.a:(.literal .text .literal.* .text.*)
+    *libaxtls.a:(.literal .text .literal.* .text.*)
     *(.irom0.literal .irom.literal .irom.text.literal .irom0.text .irom.text .irom.text.*)
     _irom0_text_end = ABSOLUTE(.);
     _flash_code_end = ABSOLUTE(.);