libsdp: Move to bluetooth-lib package

Instead of creating a separate libsdp package, use LIB_PACKAGE to
ship this in bluetooth-lib.

MFC after: 1 day
Reviewed by: bapt
Sponsored by: https://www.patreon.com/bsdivy
Differential Revision: https://reviews.freebsd.org/D52790

(cherry picked from commit 41ee4321cc528b1f72d6a674fafdd5337be83f95)