dt-bindings: Rename Exynos to lowercase

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

"EXYNOS" is not an abbreviation but a regular trademarked name.
Therefore it 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.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/media/exynos-jpeg-codec.txt

-Samsung S5P/EXYNOS SoC series JPEG codec
+Samsung S5P/Exynos SoC series JPEG codec
 
 Required properties:
 

Documentation/devicetree/bindings/media/exynos5-gsc.txt

 * Samsung Exynos5 G-Scaler device
 
-G-Scaler is used for scaling and color space conversion on EXYNOS5 SoCs.
+G-Scaler is used for scaling and color space conversion on Exynos5 SoCs.
 
 Required properties:
 - compatible: should be one of

Documentation/devicetree/bindings/media/samsung-fimc.txt

-Samsung S5P/EXYNOS SoC Camera Subsystem (FIMC)
+Samsung S5P/Exynos SoC Camera Subsystem (FIMC)
 ----------------------------------------------
 
 The S5P/Exynos SoC Camera subsystem comprises of multiple sub-devices

Documentation/devicetree/bindings/media/samsung-mipi-csis.txt

-Samsung S5P/EXYNOS SoC series MIPI CSI-2 receiver (MIPI CSIS)
+Samsung S5P/Exynos SoC series MIPI CSI-2 receiver (MIPI CSIS)
 -------------------------------------------------------------
 
 Required properties:

Documentation/devicetree/bindings/phy/samsung-phy.txt

-Samsung S5P/EXYNOS SoC series MIPI CSIS/DSIM DPHY
+Samsung S5P/Exynos SoC series MIPI CSIS/DSIM DPHY
 -------------------------------------------------
 
 Required properties:
@@ -27,7 +27,7 @@ the PHY specifier identifies the PHY and its meaning is as follows:
 supports additional fifth PHY:
   4 - MIPI CSIS 2.
 
-Samsung EXYNOS SoC series Display Port PHY
+Samsung Exynos SoC series Display Port PHY
 -------------------------------------------------
 
 Required properties:
@@ -38,7 +38,7 @@ Required properties:
 		      control pmu registers for power isolation.
 - #phy-cells : from the generic PHY bindings, must be 0;
 
-Samsung S5P/EXYNOS SoC series USB PHY
+Samsung S5P/Exynos SoC series USB PHY
 -------------------------------------------------
 
 Required properties: