d/steamvr_lh: rolling scanout values for Vive Pro 2
Signed-off-by: MatrixFurry <did:plc:zmjoeu3stwcn44647rhxa44o>Part-of: <https://gitlab.freedesktop.org/monado/monado/-/merge_requests/2615>
matrixfurry.com 4 months ago 90eb04f2 6730257b