Remove old gk20a_err() and gk20a_warn as they're no longer used. JIRA NVGPU-16 Change-Id: Id07aae20648631ef5aa0ee47d6a935055ce784dd Signed-off-by: Terje Bergstrom <tbergstrom@nvidia.com> Reviewed-on: http://git-master/r/1457358 Reviewed-by: Alex Waterman <alexw@nvidia.com> Reviewed-by: svccoveritychecker <svccoveritychecker@nvidia.com> GVS: Gerrit_Virtual_Submit