* [style] Use same style for cmake `set` command
* [build] Specify CMAKE_FIND_ROOT_PATH_MODE_PACKAGE in xxx.toolchain.cmake
* [build] Allow user passing args for cmake find cmds
* Add POWER8 VSX toolchains
POWER8, though slower than POWER9, is still used in the wild; these
toolchains should still be much faster on POWER8 than POWER8 without VSX
optimizations.
* VSX toolchains: set -cpu arg in QEMU CI tests