MIPS: Loongson: CS5536: Fix ISA support

The function _wrmsr() called by divil_lbar_disable()/enable() should be
called with the offset as the argument.

Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: Zhang Le <r0bertz@gentoo.org>
Patchwork: http://patchwork.linux-mips.org/patch/1252/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>