Revert "of/exynos_g2d: Add Bindings for exynos G2D driver"

This reverts commit 09495dda.
The description is incomplete and the location of this file
is incorrect. Based on discussion with the Samsung media and DRM subsystem
maintainers, the documentaion of Samsung G2D bindings has been placed at:
Documentation/devicetree/bindings/gpu/samsung-g2d.txt

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Inki Dae <inki.dae@samsung.com>