i965: Only magnify depth for 3D textures, not array textures.

When BaseLevel > 0, we magnify the dimensions to fill out the size of
miplevels [0..BaseLevel).  In particular, this was magnifying depth,
thinking that the depth doubles at each level.  This is perfectly
reasonable for 3D textures, but dead wrong for array textures.

Changing the depth != 1 condition to a target == GL_TEXTURE_3D check
should make this only happen in the appropriate cases.

Fixes about 32 dEQP tests:
- dEQP-GLES31.functional.texture.gather.*.level_{1,2}

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Matt Turner <mattst88@gmail.com>
Cc: mesa-stable@lists.freedesktop.org
(cherry picked from commit 4ba7ad6cc1)

src/mesa/drivers/dri/i965/intel_tex_image.c

@@ -51,7 +51,7 @@ intel_miptree_create_for_teximage(struct brw_context *brw,
       width <<= 1;
       if (height != 1)
          height <<= 1;
-      if (depth != 1)
+      if (intelObj->base.Target == GL_TEXTURE_3D)
          depth <<= 1;
    }