ddr: altera: Internal mem_calibrate() cleanup part 4

ddr: altera: Internal mem_calibrate() cleanup part 4

This is kind of microseries-within-series indent cleanup.
Rework the code for the last loop within the mega-loop
to make it actually readable and not an insane cryptic pile
of indent failure.

It is likely that this patch has checkpatch warnings, but
for the sake of not breaking the code, these are ignored.

No functional change.

Signed-off-by: Marek Vasut <marex@denx.de>