ARM: dts: exynos5250: Add eDP/LVDS bridge to Spring

Signed-off-by: Ajay Kumar <ajaykumar.rs@samsung.com>
[AF: Redone for v6]
Signed-off-by: Andreas Färber <afaerber@suse.de>
TEST_ONLY: Disable dp-controller, lvds-bridge, panel

Signed-off-by: Andreas Färber <afaerber@suse.de>