[Stable-9.1.1 23/32] hw/loongarch/virt: Add description for virt machine type

[Michael Tokarev]

From: Bibo Mao <maobibo@loongson.cn>

The description about virt machine type is removed by mistake, add
new description here. Here is output result with command
"./qemu-system-loongarch64 -M help"

Supported machines are:
none                 empty machine
virt                 QEMU LoongArch Virtual Machine (default)
x-remote             Experimental remote machine

Without the patch, it shows as follows:
Supported machines are:
none                 empty machine
virt                 (null) (default)
x-remote             Experimental remote machine

Fixes: ef2f11454c(hw/loongarch/virt: Replace Loongson IPI with LoongArch IPI)
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Michael Tokarev <mjt@tls.msk.ru>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
(cherry picked from commit 4265b4f358436252ef36164566f316458f1df671)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

diff --git a/hw/loongarch/virt.c b/hw/loongarch/virt.c
index 29040422aa..8e80110b24 100644
--- a/hw/loongarch/virt.c
+++ b/hw/loongarch/virt.c
@@ -1390,6 +1390,7 @@ static void virt_class_init(ObjectClass *oc, void *data)
     mc->init = virt_init;
     mc->default_cpu_type = LOONGARCH_CPU_TYPE_NAME("la464");
     mc->default_ram_id = "loongarch.ram";
+    mc->desc = "QEMU LoongArch Virtual Machine";
     mc->max_cpus = LOONGARCH_MAX_CPUS;
     mc->is_default = 1;
     mc->default_kernel_irqchip_split = false;
-- 
2.39.5