[edk2-platforms] Platform/Loongson: Modify Readme of Loongarch.

[edk2-platforms] Platform/Loongson: Modify Readme of Loongarch.

[xianglai]

Fix the compilation description error in the Readme file.

Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Bibo Mao <maobibo@loongson.cn>
Cc: Chao Li <lichao@loongson.cn>
Cc: Leif Lindholm <quic_llindhol@quicinc.com>
Cc: Liming Gao <gaoliming@byosoft.com.cn>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Signed-off-by: xianglai li <lixianglai@loongson.cn>
---
 Platform/Loongson/LoongArchQemuPkg/Readme.md | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Platform/Loongson/LoongArchQemuPkg/Readme.md b/Platform/Loongson/LoongArchQemuPkg/Readme.md
index 7b11905f14..c31ac13ffc 100644
--- a/Platform/Loongson/LoongArchQemuPkg/Readme.md
+++ b/Platform/Loongson/LoongArchQemuPkg/Readme.md
@@ -25,9 +25,13 @@
     $ mkdir -p $WORKSPACE
     $ cd $WORKSPACE
     $ git clone https://github.com/tianocore/edk2.git
+    $ cd edk2
     $ git submodule update --init
+    $ cd ..
     $ git clone https://github.com/tianocore/edk2-platforms.git
+    $ cd edk2-platforms
     $ git submodule update --init
+    $ cd ..
     $ git clone https://github.com/tianocore/edk2-non-osi.git
     $ export PACKAGES_PATH=$PWD/edk2:$PWD/edk2-platforms:$PWD/edk2-non-osi
 
-- 
2.31.1