docs/system: Update MIPS CPU documentation

Add Loongson-3A CPU models description.

Signed-off-by: Huacai Chen <chenhc@lemote.com>
Message-Id: <1602059975-10115-10-git-send-email-chenhc@lemote.com>
[PMD: Split patch in 2: CPU / machine]
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

docs/system/cpu-models-mips.rst.inc

@@ -48,11 +48,17 @@ across all desired hosts.
 ``I6400``
     MIPS64 Processor (Release 6, 2014)
 
+``Loongson-2E``
+    MIPS64 Processor (Loongson 2, 2006)
+
 ``Loongson-2F``
     MIPS64 Processor (Loongson 2, 2008)
 
-``Loongson-2E``
-    MIPS64 Processor (Loongson 2, 2006)
+``Loongson-3A1000``
+    MIPS64 Processor (Loongson 3, 2010)
+
+``Loongson-3A4000``
+    MIPS64 Processor (Loongson 3, 2018)
 
 ``mips64dspr2``
     MIPS64 Processor (Release 2, 2006)