#define SPI_CS   5     // IO5 (D1)
 #define SPI_MOSI 13     // IO13 (D7)
 #define SPI_MISO 12     // IO12 (D6)
 #define SPI_SCK  14     // IO14 (D5)
 #define AS_INT    15     // IO15  (D8)
 #define NEOPIXEL  4     // IO4  (D2)
 

I initially tried to hook the device CS to D8 but that prevented the ESP8266 from booting.
Instead I put the CS on D1 and placed the INT on D8. This worked.