fuzzer: Remove AX211 macro definitions

The macro definitions are exclusive to the AX211.  We're on the AX215 now,
so remove the definitions in preparation for coming up with new ones.
sd: Add 0x40 to pins, to make them printable

When we read the pins (which return a result between 0x00 and 0x3f), add
in 0x40.  This brings the result into the printable range, and makes it
more visually distinct when printing out the hex values.
fuzz: Randomize value transitions

Currently, two random values are selected for the SFR, and the code
toggles between these two values.

This patch will now do that half the time.  25% of the time, it will not
change the value at all.  25% of the time, the value will be the compliment.
fuzz: Randomize the amount of time the AX215 waits

The AX215 waits for up to 2^18 cycles before flipping the GPIOs back.
Make this random rather than fixed in fuzzer.c, by patching the binary
prior to uploading it to the card.