video: fbdev: atmel_lcdfb: remove set but not used variable 'pdata'

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/video/fbdev/atmel_lcdfb.c: In function 'atmel_lcdfb_remove':
drivers/video/fbdev/atmel_lcdfb.c:1255:28: warning:
 variable 'pdata' set but not used [-Wunused-but-set-variable]

It's not used since commit 42110e91 ("video: atmel_lcdfb: introduce
atmel_lcdfb_power_control")

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>