A kbuild and kconfig maintainer change

For eight years, Masahiro Yamada has been the sole maintainer of thekernel's build and configuration systems - two complex pieces ofinfrastructure that many people interact with, but few truly understand.Yamada has just steppeddown from that position. Maintenance of the build system will be takenup by Nathan Chancellor and Nicolas Schier (in the "odd fixes" capacity),while the configuration system is now entirely unmaintained.

Thanks are due to Yamada for all that work, and to Chancellor and Schierfor stepping up. Hopefully a way will be found to better support theseimportant subsystems in the near future.