boards/airfy-beacon: added I2C configuration

boards/airfy-beacon/Makefile.features

@@ -4,6 +4,7 @@ FEATURES_PROVIDED += periph_cpuid
 FEATURES_PROVIDED += periph_flashpage
 FEATURES_PROVIDED += periph_gpio
 FEATURES_PROVIDED += periph_hwrng
+FEATURES_PROVIDED += periph_i2c
 FEATURES_PROVIDED += periph_rtt
 FEATURES_PROVIDED += periph_spi
 FEATURES_PROVIDED += periph_timer

boards/airfy-beacon/include/periph_conf.h

@@ -94,6 +94,28 @@ static const timer_conf_t timer_config[] = {
 #define SPI_0_PIN_SCK       15
 /** @} */
 
+/**
+ * @brief   I2C (TWI) configuration
+ * @{
+ */
+static const i2c_conf_t i2c_config[] = {
+    {
+        .dev     = NRF_TWI0,
+        .pin_scl = 7,
+        .pin_sda = 8,
+        .ppi     = 0
+    },
+    {
+        .dev     = NRF_TWI1,
+        .pin_scl = 9,
+        .pin_sda = 10,
+        .ppi     = 1
+    }
+};
+
+#define I2C_NUMOF           (sizeof(i2c_config) / sizeof(i2c_config[0]))
+/** @} */
+
 /**
  * @brief   ADC configuration
  *