Move typdef from RCTImageView -> RCTUIKit (#1617)

Libraries/Image/RCTImageView.h

@@ -6,14 +6,6 @@
  */
 
 #import <React/RCTUIKit.h> // TODO(macOS GH#774)
-#if !TARGET_OS_OSX // [TODO(macOS GH#774)
-#import <UIKit/UIKit.h>
-#else // [TODO(macOS GH#774)
-typedef NS_ENUM(NSInteger, UIImageRenderingMode) {
-    UIImageRenderingModeAlwaysOriginal,
-    UIImageRenderingModeAlwaysTemplate,
-};
-#endif // ]TODO(macOS GH#774)
 #import <React/RCTView.h>
 #import <React/RCTResizeMode.h>
 

React/Base/RCTUIKit.h

@@ -321,6 +321,11 @@ NS_INLINE NSEdgeInsets UIEdgeInsetsMake(CGFloat top, CGFloat left, CGFloat botto
 // UIImage
 @compatibility_alias UIImage NSImage;
 
+typedef NS_ENUM(NSInteger, UIImageRenderingMode) {
+    UIImageRenderingModeAlwaysOriginal,
+    UIImageRenderingModeAlwaysTemplate,
+};
+
 #ifdef __cplusplus
 extern "C"
 #endif