kernel-dev: Fix the locations of .config and source directory

The locations of the kernel .config file and source direcotry
moved a couple releases ago.  Updated the documentation
accordingly.

Also added a note explaining how to check the expansion of
variables, which servs a couple of purposes:

 * For curious readers, shows them how to understand where
   these variables come from and how they are used.

 * For suspicious readers, shows them how they can verify that
   the variables in the documentation are actually correct.

Author: Tom Zanussi <tom.zanussi@linux.intel.com>
(From yocto-docs rev: af3613b6178122b9e5452529a087143b3fe98495)

Signed-off-by: Scott Rifenbark <srifenbark@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

0 files changed, 0 insertions, 0 deletions