Use UIKit for tvOS PCH instead of Foundation.

lib/cocoapods/generator/header.rb

@@ -84,6 +84,7 @@ module Pod
       def generate_platform_import_header
         case platform.name
         when :ios then "#import <UIKit/UIKit.h>\n"
+        when :tvos then "#import <UIKit/UIKit.h>\n"
         when :osx then "#import <Cocoa/Cocoa.h>\n"
         else "#import <Foundation/Foundation.h>\n"
         end

spec/unit/generator/header_spec.rb

@@ -42,7 +42,7 @@ module Pod
 
     it 'imports Foundation for tvOS platforms' do
       @gen.stubs(:platform).returns(Pod::Platform.tvos)
-      @gen.generate.should.include?('#import <Foundation/Foundation.h>')
+      @gen.generate.should.include?('#import <UIKit/UIKit.h>')
     end
 
     it 'writes the header file to the disk' do