cros_ec_debugfs: Pass proper struct sizes to cros_ec_cmd_xfer()

We should output or receive every byte in the param / reply struct,
unrelated to the pointer size.

Signed-off-by: Shawn Nematbakhsh <shawnn@chromium.org>
Reviewed-by: Gwendal Grignou <gwendal@chromium.org>
[bleung: Picked from crosreview.com/444085 for cros_ec_debugfs.c only.
 cros_ec.c upstream had a different cros_ec_sleep_event which didn't
 have the sizeof issue]
Signed-off-by: Benson Leung <bleung@chromium.org>