configure: disable mipsfpu for loongson3

MIPSFPU optimization does't support FATE correctly on Loongson-3.
Signed-off-by: ZhouXiaoyong <zhouxiaoyong@loongson.cn>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

configure

@@ -3923,7 +3923,7 @@ elif enabled mips; then
             check_ldflags "-mabi=64"
         ;;
         loongson3*)
-            enable mipsfpu
+            disable mipsfpu
             disable mips32r2
             disable mips32r5
             disable mips64r6