drm/panel: Changes for v3.17-rc1

Panels can now be more finely controlled via .prepare() and .unprepare()
callbacks in addition to .enable() and .disable(). New kerneldoc details
what they are supposed to do and when they should be called.

The simple panel driver gained support for a couple of new panels and it
is now possible to specify additional delays during power up and power
down sequences if panels require it.

DSI devices can now advertise that they support non-continuous clock
mode which will allow DSI host controllers to disable the high speed
clock after transmissions to save power.

* tag 'drm/panel/for-3.17-rc1' of git://anongit.freedesktop.org/tegra/linux: (30 commits)
  drm/panel: simple: Use devm_gpiod_get_optional()
  drm/dsi: Replace upcasting macro by function
  drm/panel: ld9040: Replace upcasting macro by function
  drm/exynos: dp: Modify driver to support drm_panel
  drm/exynos: Move DP setup into commit()
  drm/panel: simple: Add AUO B133HTN01 panel support
  drm/panel: simple: Support delays in panel functions
  drm/panel: simple: Add proper definition for prepare and unprepare
  drm/panel: s6e8aa0: Add proper definition for prepare and unprepare
  drm/panel: ld9040: Add proper definition for prepare and unprepare
  drm/tegra: Add support for panel prepare and unprepare routines
  drm/exynos: dsi: Add support for panel prepare and unprepare routines
  drm/exynos: dpi: Add support for panel prepare and unprepare routines
  drm/panel: simple: Add dummy prepare and unprepare routines
  drm/panel: s6e8aa0: Add dummy prepare and unprepare routines
  drm/panel: ld9040: Add dummy prepare and unprepare routines
  drm/panel: Provide convenience wrapper for .get_modes()
  drm/panel: add .prepare() and .unprepare() functions
  drm/panel: simple: Remove simple-panel compatible
  drm/panel: simple: Add Innolux N116BGE panel support
  ...