Update xcconfig

Author: kylef

Configurations/UniversalFramework_Base.xcconfig

@@ -12,7 +12,7 @@ VALID_ARCHS[sdk=iphoneos*]             = arm64 armv7 armv7s
 VALID_ARCHS[sdk=iphonesimulator*]      = i386 x86_64
 VALID_ARCHS[sdk=watchos*]              = armv7k
 VALID_ARCHS[sdk=watchsimulator*]       = i386
-VALID_ARCHS[sdk=appletv*]              = arm64
+VALID_ARCHS[sdk=appletvos*]            = arm64
 VALID_ARCHS[sdk=appletvsimulator*]     = x86_64
 
 // Dynamic linking uses different default copy paths