drm/bridge: ptn3460: Few trivial cleanups

This patch does the following changes:
	-- Use usleep_range instead of udelay.
	-- Remove driver_private member from ptn3460 structure.
	-- Make all possible functions and structures static.
	-- Use dev_err for non-DRM errors.
	-- Arrange header files alphabetically.
	-- s/edid/EDID in all error messages.

Signed-off-by: Ajay Kumar <ajaykumar.rs@samsung.com>
Acked-by: Inki Dae <inki.dae@samsung.com>
Tested-by: Rahul Sharma <rahul.sharma@samsung.com>
Tested-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Tested-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Tested-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk>
Signed-off-by: Thierry Reding <treding@nvidia.com>