MAINTAINERS: add entry for Amlogic Thermal driver

Add myself as maintainer for Amlogic Thermal driver.

Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Guillaume La Roque <glaroque@baylibre.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20191004090114.30694-8-glaroque@baylibre.com