GL3 has support for clip planes but they are used differently and
involve writing to a builtin output variable in the vertex shader. The
current clip plane code assumes it is only used with a fixed function
driver and tries to directly push to the matrix builtins. This
obviously won't work on GL3 so for now let's just disable clip planes.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
(cherry picked from commit 5f621589467ab961f5130590298dc8e26d658a92)