zephyr: test: Add chgstate test for idle when no ac is present
zephyr: test: Add chgstate test for idle when no ac is present

Test the error condition when no AC is present and we attempt to set idle
to 'on'.

BRANCH=none
BUG=b:221471404
TEST=zmake configure --clobber --test test-drivers

Signed-off-by: Yuval Peress <50dc11c009bd4d7e9d9d15a383c1743ce5ee82ef@google.com>
Change-Id: I26cdac96b0be992b6937f2b85dad3f9666c14c00
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3500295
Reviewed-by: Jeremy Bettis <4df7b5147fee087dca33c181f288ee7dbf56e022@chromium.org>

coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec