platform/chrome: cros_ec_proto: add Kunit tests for getting cmd mask

cros_ec_get_host_command_version_mask() expects to receive
sizeof(struct ec_response_get_cmd_versions) from send_command().
The payload is valid only if the return value is positive.

Add Kunit tests for returning 0 from send_command() in
cros_ec_get_host_command_version_mask().

Note that because the 2 cros_ec_get_host_command_version_mask() use the
same `ver_mask`.  cros_ec_proto_test_query_all_no_host_sleep_return0()
polluates the `ver_mask` and returns 0 on the second send_command() to
make sure the second cros_ec_get_host_command_version_mask() doesn't
take the garbage from the previous call.

Reviewed-by: Guenter Roeck <groeck@chromium.org>
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
Link: https://lore.kernel.org/r/20220609084957.3684698-18-tzungbi@kernel.org