ozone/drm: Use DRM_FORMAT_MOD_INVALID to indicate absence of modifier

Upstream has allocated DRM_FORMAT_MOD_INVALID as a special modifier
that indicates the absence of a modifier. This is the legacy mode
where the kernel gets the tiling/layout information through back
channels, typically as a property of the BO.

It's a little more concise that passing addfb_flags around as we did
before and can be encoded into the NativePixmap handle as well.

Bug: b:70546200, b:71416883, chromium:789292, b:69238712, b:68003124
Change-Id: I4340355e56d4117afebb06e1d96d4f8b93900a6e
Reviewed-on: https://chromium-review.googlesource.com/885904
Commit-Queue: Kristian H. Kristensen <[email protected]>
Reviewed-by: Daniele Castagna <[email protected]>
Cr-Commit-Position: refs/heads/master@{#532536}
2 files changed