Revert "core: update Seat to wl_seat_listener version 2"

This reverts commit 2789da9476ec39bbdd5dca1684ce5f2976505357.

Compilation is not backwards compatible with 1.0 and 1.1.
core: explicitly bind to version 1 of wl_seat

Signed-off-by: U. Artie Eoff <ullysses.a.eoff@intel.com>