pw_bluetooth: Delete AttNotifyOverAcl

Remove compounded header packet in accordance with discussed
design principles for Emboss packets.

Change-Id: Ica0c353383ba53084d56c6664b386b21943763bc
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/237259
Lint: Lint 🤖 <android-build-ayeaye@system.gserviceaccount.com>
Reviewed-by: David Rees <drees@google.com>
Presubmit-Verified: CQ Bot Account <pigweed-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Ben Lawson <benlawson@google.com>
Commit-Queue: Auto-Submit <auto-submit@pigweed-service-accounts.iam.gserviceaccount.com>
Docs-Not-Needed: Austin Foxley <afoxley@google.com>
Pigweed-Auto-Submit: Austin Foxley <afoxley@google.com>

pw_bluetooth/public/pw_bluetooth/att.emb

@@ -104,11 +104,3 @@ struct AttHandleValueNtf(attribute_size: UInt:16):
     [requires: this > 0]
 
   $next [+attribute_size]  UInt:8[attribute_size]  attribute_value
-
-
-struct AttNotifyOverAcl(attribute_size: UInt:16):
-  -- ATT_HANDLE_VALUE_NTF over L2CAP B-frame over ACL packet.
-  0     [+hci.AclDataFrameHeader.$size_in_bytes]  hci.AclDataFrameHeader             acl_header
-  $next [+l2cap.BFrameHeader.$size_in_bytes]      l2cap.BFrameHeader                 l2cap_header
-  let att_size = AttHandleValueNtf.$min_size_in_bytes+attribute_size
-  $next [+att_size]                               AttHandleValueNtf(attribute_size)  att_handle_value_ntf