bootstd: Correct the name of the QEMU bootmeth

This does not relate to sandbox. Correct the name.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/boot/bootmeth_qfw.c b/boot/bootmeth_qfw.c
index ecd4b08..8ebbc3e 100644
--- a/boot/bootmeth_qfw.c
+++ b/boot/bootmeth_qfw.c
@@ -76,7 +76,7 @@
 {
 	struct bootmeth_uc_plat *plat = dev_get_uclass_plat(dev);
 
-	plat->desc = "Sandbox boot for testing";
+	plat->desc = "QEMU boot using firmware interface";
 
 	return 0;
 }