Rather than specifying SHIELD via Kconfig, we move it to being
specified via the command line, similar to board.
So we can do:
-DSHIELD=x_nucleo_iks01a1
or, for multiple shields:
-DSHIELD="x_nucleo_iks01a1 frdm_kw41z"
Following cmake change, update x_nucleo_iks01a1 sample in order
not to enable CONFIG option anymore but set SHIELD cmake option.
Last, update documentation to reflect this change.
Signed-off-by: Erwan Gouriou <erwan.gouriou@linaro.org>
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
0115c47b69