[BSP] Add sd.bin in command

bsp/qemu-vexpress-a9/qemu-dbg.bat

@@ -1 +1,6 @@
-qemu-system-arm -M vexpress-a9 -kernel rtthread.elf -serial vc -serial vc -S -s
+@echo off
+if exist sd.bin goto run
+qemu-img create -f raw sd.bin 64M
+
+:run
+qemu-system-arm -M vexpress-a9 -kernel rtthread.elf -serial vc -serial vc -sd sd.bin -S -s

bsp/qemu-vexpress-a9/qemu.bat

@@ -1 +1,6 @@
-qemu-system-arm -M vexpress-a9 -kernel rtthread.elf -serial vc -serial vc
+@echo off
+if exist sd.bin goto run
+qemu-img create -f raw sd.bin 64M
+
+:run
+qemu-system-arm -M vexpress-a9 -kernel rtthread.elf -serial vc -serial vc -sd sd.bin