Taal panel driver supports two kinds of backlight control: 1) using DSI
commands sent to the panel to control the backlight, 2) calling function
pointers going to the board file to control the backlight.

The second option is a bit hacky, and will no longer be needed when the
PWM driver supports the backlight features. After that we can use the
standard PWM backlight driver.

This patch removes the second backlight control mechanism, and adds a
boolean field, use_dsi_backlight, to nokia_dsi_panel_data which the
board file can use to inform whether the panel driver should use DSI
commands to control the backlight.
Signed-off-by: NTomi Valkeinen <tomi.valkeinen@ti.com>

ULPS is a low power state where the DSI lanes are kept at ground. This
patch implements ULPS by having a DSI bus inactivity timer which
triggers the entry to ULPS. ULPS exit will happen automatically when the
driver needs to do something on the DSI lanes.

The ulps_timeout is configurable from board file or via sysfs.
Additionally another sysfs file, "ulps", can be used to check the
current ULPS state, or to manually enter or exit ULPS.
Signed-off-by: NTomi Valkeinen <tomi.valkeinen@ti.com>

ESD check in Taal driver is currently on/off feature with hardcoded
interval. This patch changes it to a configurable interval, which can be
set from the board file.
Signed-off-by: NTomi Valkeinen <tomi.valkeinen@ti.com>

arch/arm/plat-omap/include/plat/nokia-dsi-panel.h is an include for the
OMAP DSS panel driver for Nokia's DSI displays. A more logical place for
it is in include/video.
Signed-off-by: NTomi Valkeinen <tomi.valkeinen@ti.com>

arch/arm/plat-omap/include/plat/display.h is an include for the OMAP DSS
driver. A more logical place for it is in include/video.
Signed-off-by: NTomi Valkeinen <tomi.valkeinen@ti.com>

Introduce a configuration struct for platform/board specific information
of Nokia DSI command mode panels, to be used in addition to struct
omap_dss_device (passed via the 'void *data' member).
Signed-off-by: NJani Nikula <ext-jani.1.nikula@nokia.com>
Signed-off-by: NTomi Valkeinen <tomi.valkeinen@nokia.com>