meta: texture rectangle textures may not have mipmaps

meta: texture rectangle textures may not have mipmaps

Avoid INVALID_OPERATION error if decompressing rectangle texture.
Setting mipmap level limits for those textures is error that must not be
hit by meta code to mislead user.

[v3/Kayden]: Resolve conflicts due to Eric picking a subset of Pauli's
original changes.

Signed-off-by: Pauli Nieminen <pauli.nieminen@linux.intel.com>
Reviewed-by: Brian Paul <brianp@vmware.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>