Add support for second SPI HW device

libraries/SPI/SPI.cpp

@@ -247,3 +247,6 @@ void SPIClass::detachInterrupt() {
 #if SPI_INTERFACES_COUNT > 0
 SPIClass SPI (NRF_SPI0,  PIN_SPI_MISO,  PIN_SPI_SCK,  PIN_SPI_MOSI);
 #endif
+#if SPI_INTERFACES_COUNT > 1
+SPIClass SPI1(NRF_SPI1, PIN_SPI1_MISO, PIN_SPI1_SCK, PIN_SPI1_MOSI);
+#endif

libraries/SPI/SPI.h

@@ -136,6 +136,9 @@ void SPIClass::transfer(void *buf, size_t count)
 #if SPI_INTERFACES_COUNT > 0
 extern SPIClass SPI;
 #endif
+#if SPI_INTERFACES_COUNT > 1
+extern SPIClass SPI1;
+#endif
 
 // For compatibility with sketches designed for AVR @ 16 MHz
 // New programs should use SPI.beginTransaction to set the SPI clock