drm/i915: WARN in case we're enabling the pipe and it's enabled

... and QUIRK_PIPEA_FORCE is not present.

I initially thought that case was impossible and just added a WARN on
it, but then I was told this case is possible due to
QUIRK_PIPEA_FORCE. So let's add a WARN that serves two purposes:
  - tell us in case we have done something wrong;
  - document the only case where we expect this.

Signed-off-by: Paulo Zanoni <[email protected]>
Reviewed-by: Damien Lespiau <[email protected]>
Signed-off-by: Daniel Vetter <[email protected]>

0 files changed, 0 insertions, 0 deletions