emul_smart_battery: Validate string property sizes
emul_smart_battery: Validate string property sizes

Add BUILD_ASSERTs to enforce that strings of sizes larger than
MAX_BLOCK_SIZE cannot be properties of the DT node that the
emul_smart_battery is emulating.

BRANCH=none
BUG=b:246652125
TEST=./twister --clobber -i -s zephyr/test/drivers/drivers.default -b
TEST=Above TEST with failing string property

Signed-off-by: Aaron Massey <79529a820df71f45023239a3663736629646cc34@google.com>
Change-Id: I5c44be1bfd1ff183a5357ea947285662d467fffc
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3910903
Code-Coverage: Zoss <345cf107e82c70959d46f59d98bddc98ce458aff@prod.google.com>
Reviewed-by: Keith Short <f6d578f97033c25f1206cb57d52f358974c82954@chromium.org>

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