Fix typo

src/ok04/counter.s

@@ -6,7 +6,7 @@
 .global delay
 delay:
     ldr         r1, =0x3F000000     @; pi peripheral address
-    orr         r1, r1, #0x3000     @; r6 = r1 | 0x3000 = 0x3F003000 timer base address
+    orr         r1, r1, #0x3000     @; r1 = r1 | 0x3000 = 0x3F003000 timer base address
     ldr         r2, [r1, #0x4]      @; time in microseconds given by the timer
     delay1$:
         ldr     r3, [r1, #0x4]      @; get timer in microseconds in each iteration