util/loongarch64: Detect LASX vector support

Reviewed-by: Song Gao <gaosong@loongson.cn>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

host/include/loongarch64/host/cpuinfo.h

@@ -8,6 +8,7 @@
 
 #define CPUINFO_ALWAYS          (1u << 0)  /* so cpuinfo is nonzero */
 #define CPUINFO_LSX             (1u << 1)
+#define CPUINFO_LASX            (1u << 2)
 
 /* Initialized with a constructor. */
 extern unsigned cpuinfo;

util/cpuinfo-loongarch.c

@@ -29,6 +29,7 @@ unsigned __attribute__((constructor)) cpuinfo_init(void)
 
     info = CPUINFO_ALWAYS;
     info |= (hwcap & HWCAP_LOONGARCH_LSX ? CPUINFO_LSX : 0);
+    info |= (hwcap & HWCAP_LOONGARCH_LASX ? CPUINFO_LASX : 0);
 
     cpuinfo = info;
     return info;