sunxi: add LPDDR3 timing from stock boot0

As we added LPDDR3 support in the former patch, we need a set of timing
info to really enable it.

Add the timing info used by stock boot0.

Signed-off-by: Icenowy Zheng <icenowy@aosc.xyz>
Acked-by: Jagan Teki <jagan@amarulasolutions.com>
Tested-by: Jagan Teki <jagan@amarulasolutions.com>