.python/SpellCheck: Add "Loongson" and "LOONGARCH" to "words" section

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=4053

Add Loongson and LOONGARCH to "words" section in cspell.base.yaml file
to avoid spelling check error.

Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Liming Gao <gaoliming@byosoft.com.cn>

Signed-off-by: Chao Li <lichao@loongson.cn>
Reviewed-by: Michael D Kinney <michael.d.kinney@intel.com>

.pytool/Plugin/SpellCheck/cspell.base.yaml

@@ -289,6 +289,8 @@
         "unrecovered",
         "cmocka",
         "unenrolling",
-        "unconfigure"
+        "unconfigure",
+        "Loongson",
+        "LOONGARCH"
     ]
 }