Update to use the recent proc_ops.
Fix possible buffer overflow: The bounds were checked by the complaining
compiler, so I do not deserve credit.

Harmonize the recipes and Makefiles for imx6-spreadspectrum and
rtc-pcf8563-guf.

The imx6-spreadspectrum is still not installed by default for imx6(ull)
devices.

BCS 746-000453