glsl: Enable split of lower UBOs and SSBO also for compute shaders

glsl: Enable split of lower UBOs and SSBO also for compute shaders

The split of Uniform blocks and shader storage block only loops
up to MESA_SHADER_FRAGMENT and igonres compute shaders.
This cause segfault when running the OpenGL ES 3.1 CTS tests
with GL_ARB_compute_shader enabled.

V2: Changed to use MESA_SHADER_STAGES instead of
MESA_SHADER_COMPUTE

Reviewed-by: Francisco Jerez <currojerez@riseup.net>
Signed-off-by: Marta Lofstedt <marta.lofstedt@linux.intel.com>