OVR_multiview requires OpenGL 3.0, so expose gl_ViewID_OVR builtin back
to GLSL 1.30 on OpenGL.
v2: Minor whitespace fix
Fixes: 328c29d600 ("mesa,glsl,gallium: add GL_OVR_multiview")
Signed-off-by: James Hogan <james@albanarts.com>
Reviewed-By: Mike Blumenkrantz <michael.blumenkrantz@gmail.com>
Reviewed-by: Zoltán Böszörményi <zboszor@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/33346>
(cherry picked from commit b774b615d2)