There is a problem with LoongArch64 exception handler, it returns a
unhandled value when we get an exception type, the correct value should
be right shifted 16 bits, so fix it.
Cc: Ray Ni <ray.ni@intel.com>
Cc: Jiaxin Wu <jiaxin.wu@intel.com>
Cc: Zhiguang Liu <zhiguang.liu@intel.com>
Cc: Dun Tan <dun.tan@intel.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Jiaxin Wu <jiaxin.wu@intel.com>
Signed-off-by: Chao Li <lichao@loongson.cn>