ARM: SAMSUNG: Remove unused plat-samsung/time.c

Signed-off-by: Naour Romain <romain.naour@openwide.fr>
Reviewed-by: Tomasz Figa <tomasz.figa@gmail.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>