backlight: add S6E63M0 AMOLED LCD Panel driver

This is S6E63M0 AMOLED LCD Panel(480x800) driver using 3-wired SPI
interface also almost features for lcd panel driver has been implemented
in here.  and I added new structure common for all the lcd panel drivers
to include/linux/lcd.h file.

LCD Panel driver needs interfaces for controlling device power such as
power on/off and reset.  these interfaces are device specific so it should
be implemented to machine code at this time, we should create new
structure for registering these functions as callbacks and also a header
file for that structure and finally registered callback functions would be
called by lcd panel driver.  such header file(including new structure for
lcd panel) would be added for all the lcd panel drivers.

If anyone provides common structure for registering such callback
functions then we could reduce unnecessary header files for lcd panel.  I
thought that suitable anyone could be include/linux/lcd.h so a new
lcd_platform_data structure was added there.

[akpm@linux-foundation.org: coding-style fixes]
[randy.dunlap@oracle.com: fix s6e63m0 kconfig]
[randy.dunlap@oracle.com: fix device attribute functions return types]
Signed-off-by: InKi Dae <inki.dae@samsung.com>
Reviewed-by: KyungMin Park <kyungmin.park.samsung.com>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>