thermal: exynos: Rename Samsung and Exynos to lowercase

Fix up inconsistent usage of upper and lowercase letters in "Samsung"
and "Exynos" names.

"SAMSUNG" and "EXYNOS" are not abbreviations but regular trademarked
names. Therefore they should be written with lowercase letters starting
with capital letter.

The lowercase "Exynos" name is promoted by its manufacturer Samsung
Electronics Co., Ltd., in advertisement materials and on website.

Although advertisement materials usually use uppercase "SAMSUNG", the
lowercase version is used in all legal aspects (e.g. on Wikipedia and in
privacy/legal statements on
https://www.samsung.com/semiconductor/privacy-global/).

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200104152107.11407-7-krzk@kernel.org

dt-bindings: thermal: samsung: Add SPDX license identifier

Replace GPL license statement with SPDX license identifier (GPL-2.0+).

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Rob Herring <robh@kernel.org>

thermal: exynos: Provide thermal_exynos.h file to be included in device tree files

This patch is a preparatory patch to be able to read Exynos thermal
configuration from the device tree.

It turned out that DTC is not able to interpret enums properly and hence
it is necessary to #define those values explicitly.

For this reason the ./include/dt-bindings/thermal/thermal_exynos.h file
has been introduced.

Signed-off-by: Lukasz Majewski <l.majewski@samsung.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>