sunxi: DRAM initialisation for sun9i

This adds DRAM initialisation code for sun9i, which calculates the
appropriate timings based on timing information for the supplied
DDR3 bin and the clock speeds used.

With this DRAM setup, we have verified DDR3 clocks of up to 792MHz
(i.e. DDR3-1600) on the A80-Q7 using a dual-channel configuration.

[wens@csie.org: Moved dram_sun9i.c to arch/arm/mach-sunxi/; style cleanup]
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
[hdegoede@redhat.com: Drop some huge non-documenting #if 0 ... #endif blocks]
[hdegoede@redhat.com: Fix checkpatch warnings]
Signed-off-by: Hans de Goede <hdegoede@redhat.com>