MIPS: Treat Loongson Extensions as ASEs

MIPS: Treat Loongson Extensions as ASEs

BugLink: https://bugs.launchpad.net/bugs/1848039
commit d2f965549006acb865c4638f1f030ebcefdc71f6 upstream.

Recently, binutils had split Loongson-3 Extensions into four ASEs:
MMI, CAM, EXT, EXT2. This patch do the samething in kernel and expose
them in cpuinfo so applications can probe supported ASEs at runtime.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: Yunqiang Su <ysu@wavecomp.com>
Cc: stable@vger.kernel.org # v4.14+
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>