sunxi: Convert H616 DRAM options to single setting

Vendor DRAM settings use TPR10 parameter to enable various features.
There are many mores features that just those that are currently
mentioned. Since new will be added later and most are not known, let's
reuse value from vendor DRAM driver as-is. This will also help adding
support for new boards.

Signed-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>