drm-uapi: Update headers from drm-next

drm-uapi: Update headers from drm-next

Pull new updates from drm-next as of the following commit:

commit a5f2fafece141ef3509e686cea576366d55cabb6
Merge: 71f4e45a4ed3 860433ed2a55
Author: Dave Airlie <airlied@redhat.com>
Date:   Wed Feb 20 12:16:30 2019 +1000

    Merge https://gitlab.freedesktop.org/drm/msm into drm-next

Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Tapani Pälli <tapani.palli@intel.com>
Reviewed-by: Eric Engestrom <eric.engestrom@intel.com>