MIPS: Netlogic: rename nlm_cop2_save/restore

Rename macro nlm_cop2_enable() to nlm_cop2_enable_irqsave() and the macro
nlm_cop2_restore to nlm_cop2_disable_irqrestore(). The new names will
reflect the functionality better, and will make nlm_cop2_restore()
available to be used later in COP2 save/restore patch.

Signed-off-by: Jayachandran C <jchandra@broadcom.com>
Cc: linux-mips@linux-mips.org
Cc: ddaney.cavm@gmail.com
Patchwork: https://patchwork.linux-mips.org/patch/5412/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>