intel: Remove check for kernel 2.6.29.

intel: Remove check for kernel 2.6.29.

Now that we require 2.6.39, there's no need to also check for 2.6.29.
Calling drm_intel_bufmgr_gem_enable_fenced_relocs() without checking
should be safe, as it simply sets a flag.

This does remove the check for zero fences available, but that doesn't
seem worth checking.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Eric Anholt <eric@anholt.net>