Update the files which contain no license information with the
'Apache-2.0' SPDX license identifier. Many source files in the tree are
missing licensing information, which makes it harder for compliance
tools to determine the correct license.
By default all files without license information are under the default
license of Zephyr, which is Apache version 2.
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
XCC is based on xcc, but is nothing like gcc and his many differences.
Instead of ifdeffing the gcc code with Xcc specifics, maintain it
standalone.
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
