rockchip/rk3399: reset system if DDR init fails

We found sdram may fail in pctl_cfg(), so we check the status in this
function. If it exceeds 100ms still in this function, we will restart
the system. We also found there are rare chances DDR training fails,
so also restart system in that case.

BUG=chrome-os-partner:57988
BRANCH=None
TEST=coreboot resets on failure and eventually the system comes up

Change-Id: Icc0688da028a8f4f81eafe36bbaa79fdf2bcea74
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: 89e45f8352
Original-Change-Id: If4e78983abcfdfe1e0e26847448d86169e598700
Original-Signed-off-by: Lin Huang <hl@rock-chips.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/397439
Original-Reviewed-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://review.coreboot.org/17045
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>

src/mainboard/google/gru/Makefile.inc

@@ -31,6 +31,7 @@ romstage-y += chromeos.c
 romstage-y += memlayout.ld
 romstage-y += pwm_regulator.c
 romstage-y += romstage.c
+romstage-y += reset.c
 romstage-y += sdram_configs.c
 
 ramstage-y += boardid.c