mesa: fix issues with texture border and array textures

mesa: fix issues with texture border and array textures

For a 1D texture array, the border only applies to the width.  For a 2D
texture array the border applies to the width and height but not the depth.
Sucha cases were  not handled correctly in _mesa_init_teximage_fields().

Note: This is a candidate for stable branches

Signed-off-by: Anuj Phogat <anuj.phogat@gmail.com>
Reviewed-by: Brian Paul <brianp@vmware.com>