i965: Fix intel_miptree_copy_teximage for GL_TEXTURE_1D_ARRAY

i965: Fix intel_miptree_copy_teximage for GL_TEXTURE_1D_ARRAY

For GL_TEXTURE_1D_ARRAY targets we store the depth of the array
in the Height field and leave Depth=1 in the underlying texture
object. When we call intel_miptree_copy_teximage in the process
of re-creating a miptree (possibily because the number of miplevels
has changed) we didn't account for this, so we where only copying
texture images for the first slice.

Reviewed-by: Jason Ekstrand <jason.ekstrand@intel.com>