drm/nouveau/disp: Always accept linear modifier

drm/nouveau/disp: Always accept linear modifier

On some chipsets, which block-linear modifiers are
supported is format-specific. However, linear
modifiers are always be supported. The prior
modifier filtering logic was not accounting for
the linear case.

Cc: stable@vger.kernel.org
Fixes: c586f30bf74c ("drm/nouveau/kms: Add format mod prop to base/ovly/nvdisp")
Signed-off-by: James Jones <jajones@nvidia.com>
Link: https://lore.kernel.org/r/20250811220017.1337-3-jajones@nvidia.com
Signed-off-by: Danilo Krummrich <dakr@kernel.org>