Only one (marginal) driver was using it, and it's been fixed to just
implement it directly.
v2: Also fix sdksyms.sh (spotted by Jesse Adkins)
v3: Also fix DESIGN.xml (spotted bu Julien Cristau)
Reviewed-by: Julien Cristau <jcristau@debian.org>
Signed-off-by: Adam Jackson <ajax@redhat.com>