fix: clk western sms bios answers latin america

CLK reads every export cartridge as Europe or USA and boots the western
BIOS for any region but Japan (StaticAnalyser.cpp:49-66,
MasterSystem.cpp:137-140). The tag named brazil without its parent, so
--region mx dropped the BIOS from the Batocera pack.

emulators/clk.yml

@@ -712,12 +712,12 @@ files:
     path: MasterSystem/bios.sms
     system: sega-mastersystem
     description: "European/US Master System BIOS"
-    region: [north-america, europe, oceania, brazil]
+    region: [north-america, latin-america, europe, oceania]
     size: 8192
     crc32: "0072ed54"
     required: false
     note: "Optional. Boots cartridge directly if absent. Loaded for every region but Japan."
-    source_ref: "Machines/Utility/ROMCatalogue.cpp:764-771, Machines/MasterSystem/MasterSystem.cpp:137-140, Analyser/Static/Sega/Target.hpp:24-29"
+    source_ref: "Machines/Utility/ROMCatalogue.cpp:764-771, Machines/MasterSystem/MasterSystem.cpp:137-140, Analyser/Static/Sega/Target.hpp:24-29, Analyser/Static/Sega/StaticAnalyser.cpp:49-66"
 
   - name: japanese-bios.sms
     path: MasterSystem/japanese-bios.sms

tests/test_region.py

@@ -509,6 +509,11 @@ class OneCodeOneRegionAnswer(unittest.TestCase):
         profiles = common.load_emulator_profiles(self.PROFILES)
         bios_sms = next(e for e in profiles["clk"]["files"] if e["name"] == "bios.sms")
         self.assertIn("oceania", bios_sms["region"])
+        # A Mexican export cartridge is analysed as Europe or USA and boots the
+        # western BIOS: only Japan selects the other one.
+        self.assertEqual(
+            region.rank(region.normalize_declared(bios_sms["region"]), ["mexico"]), 0
+        )
         tagged = {
             e["name"]: e.get("region") for e in profiles["kronos"]["files"]
             if e.get("archive") == "stvbios.zip" and e["name"].startswith("epr-")