drivers/rtc/rtc-pl031.c: remove unused #include <linux/version.h>

Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com>
Acked-by: Wan ZongShun <mcuos.com@gmail.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>