thermal: imx_sc_thermal: Align imx sc thermal msg structs to 4

The i.MX SCU API strongly assumes that messages are composed out
of 4-bytes words but some of our message structs have odd sizeofs,
use __packed __aligned(4) to avoid potential oopses.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/1583117485-30922-1-git-send-email-Anson.Huang@nxp.com