Refresh several defconfig files to (1) bring them up-to-date, and (2) to confirm that no bugs were introduced in recent massive Kconfig file changes

Support for the older, manual configurations has been completely removed from the NuttX build system

configs/rgmp/x86/cxxtest: Configuration converted to use the kconfig-frontends tools.  This completes the conversion of all configurations to the newer format

configs/ne64badge/ostest and demo9s12nec64/ostest: Configurations onverted to use the kconfig-frontends tools