etnaviv: Implement PIPE_FACE_FRONT_AND_BACK

Handling of cull face GL_FRONT_AND_BACK, that is PIPE_FACE_FRONT_AND_BACK, was missing. In such setup, the blob sets PA_CONFIG to zero, however it is sufficient to set VIVS_PA_CONFIG_FILL_MODE=POINT.

This fixes: dEQP-GLES2.functional.rasterization.culling.both_triangles dEQP-GLES2.functional.rasterization.culling.both_triangles_reverse dEQP-GLES2.functional.rasterization.culling.both_triangle_strip dEQP-GLES2.functional.rasterization.culling.both_triangle_strip_reverse dEQP-GLES2.functional.rasterization.culling.both_triangle_fan dEQP-GLES2.functional.rasterization.culling.both_triangle_fan_reverse

Signed-off-by: Marek Vasut marex@denx.de