pio_1hz.py: Fix off-by-one cycle issue

Fixes raspberrypi#55

Author: stigbjorlykke

pio/pio_1hz.py

@@ -15,9 +15,10 @@ def blink_1hz():
     nop()                       [29]
     jmp(x_dec, "delay_high")
 
-    # Cycles: 1 + 7 + 32 * (30 + 1) = 1000
+    # Cycles: 1 + 1 + 6 + 32 * (30 + 1) = 1000
+    nop()                       [29]
     set(pins, 0)
-    set(x, 31)                  [6]
+    set(x, 31)                  [5]
     label("delay_low")
     nop()                       [29]
     jmp(x_dec, "delay_low")