MIPS: Netlogic: Use CPU_XLR instead of NLM_XLR

The CPU_XLR config variable is sufficient for XLR compilation, the
variable NLM_XLR can be removed.

Signed-off-by: Jayachandran C <jayachandranc@netlogicmicro.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2962/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>