boards/mcb2388: configure second SPI bus

SPI0 will always clash with the pins of the LCD display, so if we
want to use both SPI and the display we need to use SPI1.

boards/mcb2388/include/periph_conf.h

@@ -20,6 +20,7 @@
 #define PERIPH_CONF_H
 
 #include "periph_cpu.h"
+#include "kernel_defines.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -83,9 +84,18 @@ static const spi_conf_t spi_config[] = {
         .pinsel_msk_miso = (BIT14 | BIT15), /* P1.23 */
         .pinsel_msk_clk  = (BIT8  | BIT9),  /* P1.20 */
     },
+    {
+        .dev = SPI1,
+        .pinsel_mosi = 0,
+        .pinsel_miso = 0,
+        .pinsel_clk  = 0,
+        .pinsel_msk_mosi = (BIT19), /* P0.9 */
+        .pinsel_msk_miso = (BIT17), /* P0.8 */
+        .pinsel_msk_clk  = (BIT15), /* P0.7 */
+    },
 };
 
-#define SPI_NUMOF           (1)
+#define SPI_NUMOF           ARRAY_SIZE(spi_config)
 /** @} */
 
 /**