drivers/video/backlight/ep93xx_bl.c: fix section mismatch

drivers/video/backlight/ep93xx_bl.c: fix section mismatch

Fix section mismatch warning as below:

WARNING: drivers/video/backlight/built-in.o(.data+0x110): Section mismatch in reference from the variable ep93xxbl_driver to the
function .init.text:ep93xxbl_probe()
The variable ep93xxbl_driver references
the function __init ep93xxbl_probe()
If the reference is valid then annotate the
variable with __init* or __refdata (see linux/init.h) or name the variable:
*_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Cc: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>