nimble/att: Use packed struct for receiving Read By Type Response
nimble/att: Use packed struct for receiving Read By Type Response

Use packed structure to map it to received mbuf instead of using
dedicated parsing function. Modern compilers generate effective code
in such case anyway.

X-Original-Commit: c3cca4259a16b116b3a17a44896195483fdc38fa

apache/mynewt-nimble,apache/mynewt-nimble,apache/mynewt-nimble,apache/mynewt-nimble,apache/mynewt-nimble