[ARM] tegra: hdmi nvhdcp driver

[ARM] tegra: hdmi nvhdcp driver

Device /dev/nvhdcpX is used to manage NVHDCP on framebuffer /dev/fbX.
These devices are created on hdmi driver initialition when it is
attached to dc. Currently only one nvhdcp device may be created. An ioctl
interface is in video/nvhdcp.h

Check for repeaters and store repeater info. userspace application
queries this status to authenticate the connection. When authentication
fails, auto-renegotiate every 1.75 seconds. Give up after 5 failed attempts,
reset after hotplug or policy change.

use TEGRA_DC_OUT_NVHDCP_POLICY_ON_DEMAND in tegra_dc_out.flags in board
panel configuration to select a different default policy at probe. Currently
only TEGRA_DC_OUT_NVHDCP_POLICY_ALWAYS_ON is supported.

Change-Id: I0db66fc86096b98d2604544061721d291523de75
Reviewed-by: Jon Mayo <jmayo@nvidia.com>
Tested-by: Jon Mayo <jmayo@nvidia.com>
Reviewed-by: Phillip Smith <psmith@nvidia.com>
Reviewed-by: Yu-Huan Hsu <yhsu@nvidia.com>
Signed-off-by: Erik Gilling <konkers@android.com>