Added missing endif that was accidentially removed in commit sandeepmistry@0524008#diff-ddd77aecb16ad4a70bea9989e9fd8022 (sandeepmistry#339)

Author: EndlessDelirium

libraries/SPI/SPI.h

@@ -155,3 +155,5 @@ extern SPIClass SPI1;
 #define SPI_CLOCK_DIV64  64 * DIVISOR
 #define SPI_CLOCK_DIV128 128 * DIVISOR
 #endif
+
+#endif