classes/sanity: check if SDKMACHINE setting has taken effect
If you try to set SDKMACHINE in a distro configuration file, it won't
take effect because by the time that is parsed the line in bitbake.conf
which includes the appropriate conf file for SDKMACHINE has already been
parsed. Check that SDK_ARCH has changed from its default value and show
an error if it hasn't in order to catch this misconfiguration.
Fixes [YOCTO #5861].
Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
