smdkv310: use spl framework for mmc spl

smdkv310 board was using mmc_spl framework for mmc spl support.
This patch migrates the framework from mmc_spl to spl.

Signed-off-by: Chander Kashyap <chander.kashyap@linaro.org>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>
6 files changed