Revert "drm/nv50-/gpio: initialise to vbios defaults during init"

This reverts commit 991083ba.

We discovered this causes problem on some Dell eDP laptops, so Apple
lose out for now, I might try and whip up a dmi based workaround for 3.6
but I'm not sure I'll get time.

Signed-off-by: Dave Airlie <airlied@redhat.com>