rk3288: add ddr driver

Supports DDR3 and LPDDR3.Supports dual channel.ddr max freq is 533mhz.
ddr timing config file in src\mainboard\google\veyron\sdram_inf
Remove dpll init in rk clk_init(), add rkclk_configure_ddr(unsigned int hz).

BUG=chrome-os-partner:29778
TEST=Build coreboot

Change-Id: I429eb0b8c365c6285fb6cfef008b41776cc9c2d9
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: 52838c68fe6963285c974af5dc5837e819efc321
Original-Change-Id: I6ddfe30b8585002b45060fe998c9238cbb611c05
Original-Signed-off-by: jinkun.hong <jinkun.hong@rock-chips.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/209465
Original-Reviewed-by: Julius Werner <jwerner@chromium.org>
Original-Commit-Queue: Julius Werner <jwerner@chromium.org>
Reviewed-on: http://review.coreboot.org/8865
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Tested-by: build bot (Jenkins)
13 files changed