[zero/SPI] adding missing library properties

libraries/SPI/library.properties

+name=SPI
+version=1.0
+author=Jonathan BAUDIN, Thibaut VIARD, Arduino
+maintainer=Arduino <info@arduino.cc>
+sentence=Enables the communication with devices that use the Serial Peripheral Interface (SPI) Bus. Specific implementation for Arduino Zero.
+paragraph=
+url=http://www.arduino.cc/en/Reference/SPI
+architectures=samd