Fix delay_us and delay_ns not showing up

src/arch/8051/include/arch/delay.h

@@ -4,6 +4,17 @@
 #include <stdint.h>
 
 void delay_ticks(uint16_t ticks);
+
+// 1 us * 9.2 MHz / 12 is 69/90
+// Warning: this will round to the nearest tick
+#define delay_us(X) \
+    delay_ticks((uint16_t)((((uint32_t)(X)) * 69UL + 89UL) / 90UL));
+
+// 1 ns * 9.2 MHz / 12 is 69/90000
+// Warning: this will round to the nearest tick
+#define delay_ns(X) \
+    delay_ticks((uint16_t)((((uint32_t)(X)) * 69UL + 89999UL) / 90000UL));
+    
 void delay_ms(int ms);
 
 #endif // _ARCH_DELAY_H