Update index.tsx (#8280)

add the “style” property for declare file

components/spin/index.tsx

@@ -9,6 +9,7 @@ export interface SpinProps {
   prefixCls?: string;
   className?: string;
   spinning?: boolean;
+  style?: React.CSSProperties;
   size?: 'small' | 'default' | 'large';
   tip?: string;
   delay?: number;