platform/chrome: lightbar: Optimize command size

platform/chrome: lightbar: Optimize command size

Enabling tracing with:
echo 1 > /sys/kernel/debug/tracing/events/cros_ec/cros_ec_request_start/enable

To monitor the command and response size. The defaults are 194 and 128 respectively:
cros_ec_request_start: version: 0, offset: 0, command: EC_CMD_LIGHTBAR_CMD, outsize: 194, insize: 128

Reduce the sizes to the expected subcommands.

Signed-off-by: Gwendal Grignou <gwendal@google.com>
Link: https://lore.kernel.org/r/20260204035036.697955-1-gwendal@google.com
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>