tests/avocado: Enable TuxRun/mips64 (big-endian) test

Now that the previous commit ("hw/mips/gt64xxx_pci: Don't
endian-swap GT_PCI0_CFGADDR") fixed the issue accessing
the GT64120 PCI config-address register on big-endian
targets, we can enable this TuxRun test.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Acked-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20230223220404.63630-1-philmd@linaro.org>

tests/avocado/tuxrun_baselines.py

@@ -270,7 +270,6 @@ def test_mips32el(self):
         """
         self.common_tuxrun(drive="driver=ide-hd,bus=ide.0,unit=0")
 
-    @skip("QEMU currently broken") # regression against stable QEMU
     def test_mips64(self):
         """
         :avocado: tags=arch:mips64