sun6i: Update Colombus defconfig settings

The Colombus defconfig settings are missing a number of settings for recently
added features, because we did not know exactly how things were hooked up.

Maxime Ripard has run various tests to get us the necessary details, this
commit updates the defconfig with this info.

This commit also updates the dram clk and zq values with values verified
by Maxime to be the ones used by the original firmware for this board.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
sunxi: mmc: Properly setup mod-clk and clock sampling phases

The sunxi mmc controller has both an internal clock divider, as well as
the divider in the mod0-clk for the mmc controller.

The internal divider cannot be used, as it conflicts with the setting of
clock sampling phases which is done in the mod0-clk, so it must be set to
0 (divide by 1).

For some reason while the kernel has had this correct from day one, the
u-boot sunxi mmc code has been using a fixed mod0-clk and setting its
internal divider depending on the desired speed. This is something which
we've inherited from the original Allwinner u-boot sources, but while this
has been fixed in Allwinner's own u-boot code at least for the A23 and later
upstream u-boot was still doing this wrong.

This commit fixes this, thereby also fixing mmc support not working reliable
on the A23 (which seems more sensitive to this) and possible also fixes some
other sunxi mmc issues.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
sun6i: Add a sigma_delta_enable paramter to clock_set_pll5()

The sun8i dram code sometimes wants to enable sigma delta mode,
add a parameter to allow this.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
sun6i: Add k and m parameters to clock_set_pll5()

The A23 (sun8i) requires different values for these then sun6i, so make them
function parameters.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
sun8i: Add dram initialization support

Based on the register / dram_para headers from the Allwinner u-boot / linux
sources + the init sequences from boot0.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>