loongarch: Add smbios command line option.

LoongArch has enabled CONFIG_SMBIOS, but didn't enable CLI '-smbios'.

Fixes: 3efa6fa1e629 ("hw/loongarch: Add smbios support")
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Song Gao <gaosong@loongson.cn>
Message-Id: <20230227035905.1290953-2-gaosong@loongson.cn>

qemu-options.hx

@@ -2585,7 +2585,7 @@ DEF("smbios", HAS_ARG, QEMU_OPTION_smbios,
     "                specify SMBIOS type 17 fields\n"
     "-smbios type=41[,designation=str][,kind=str][,instance=%d][,pcidev=str]\n"
     "                specify SMBIOS type 41 fields\n",
-    QEMU_ARCH_I386 | QEMU_ARCH_ARM)
+    QEMU_ARCH_I386 | QEMU_ARCH_ARM | QEMU_ARCH_LOONGARCH)
 SRST
 ``-smbios file=binary``
     Load SMBIOS entry from binary file.