USB: ehci-s5p: Add support for device tree

This patch adds support to parse probe data for
ehci driver for exynos using device tree

Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org>
Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com>
Signed-off-by: Vivek Gautam <gautam.vivek@samsung.com>
Acked-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>