mesa: Set DriverFlags.NewArray together with vbo...recalculate_inputs.

mesa: Set DriverFlags.NewArray together with vbo...recalculate_inputs.

Both mean something very similar and are set at the same time now.
For that vbo module to be set from core mesa, implement a public vbo
module method to set that flag. In the longer term the flag should
vanish in favor of a driver flag of the appropriate driver.

Reviewed-by: Brian Paul <brianp@vmware.com>
Signed-off-by: Mathias Fröhlich <Mathias.Froehlich@web.de>