ARM: dts: exynos: Fix DTC unit name warnings in Exynos5250

Fix following DTC warnings in all Exynos5250 boards:

Warning (unit_address_vs_reg): Node /dp-controller@145B0000/display-timings/timing@0 has a unit name, but no reg property
Warning (unit_address_vs_reg): Node /usb@12000000 has a unit name, but no reg property
Warning (unit_address_vs_reg): Node /usb@12000000/dwc3 has a reg or ranges property, but no unit name
Warning (unit_address_vs_reg): Node /hdmi has a reg or ranges property, but no unit name
Warning (unit_address_vs_reg): Node /mixer has a reg or ranges property, but no unit name
Warning (unit_address_vs_reg): Node /video-phy@10040720 has a unit name, but no reg property
Warning (unit_address_vs_reg): Node /fixed-regulator@0 has a unit name, but no reg property
Warning (unit_address_vs_reg): Node /fixed-regulator@1 has a unit name, but no reg property
Warning (unit_address_vs_reg): Node /fixed-regulator@2 has a unit name, but no reg property
Warning (unit_address_vs_reg): Node /i2c@12C70000/trackpad has a reg or ranges property, but no unit name
Warning (unit_address_vs_reg): Node /i2c@12CD0000/lvds-bridge@20/ports/port@0 has a unit name, but no reg property
Warning (unit_address_vs_reg): Node /i2c@12CD0000/lvds-bridge@20/ports/port@1 has a unit name, but no reg property
Warning (unit_address_vs_reg): Node /i2c-arbitrator/i2c@0/embedded-controller has a reg or ranges property, but no unit name
Warning (unit_address_vs_reg): Node /i2c-arbitrator/i2c@0/power-regulator has a reg or ranges property, but no unit name
Warning (unit_address_vs_reg): Node /i2c@12CA0000/embedded-controller has a reg or ranges property, but no unit name

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>