systemd: Use ${ROOT_HOME} instead of /root

systemd avoids using nss lookups for the root user, so
naturally it assumes that root's home directory is /root.
In OE that's not the case, and it can lead to long delays when
shutting down due to user shutdown unit failures.

Signed-off-by: Dan McGregor <dan.mcgregor@usask.ca>
Signed-off-by: Ross Burton <ross.burton@intel.com>
nativesdk-cmake: Adjust toolchain paths dynamically

This patch adds a flexible way to configure the CMake in SDKs. It adds
a toolchain configuration script which supports subscripts for
extensions, as for example Qt5.

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>