sun6i: Add sunxi_get_ss_bonding_id() function

Add a sunxi_get_ss_bonding_id() function, and use it to differentiate between
the A31s and the A31.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
sun6i: dram: Do not try to initialize a second dram chan on A31s

The A31s only has one dram channel, so do not bother with trying to initalize
a second channel.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
sun6i: Drop some "unknown magic" from dram init

This bit of code is the rtc ram being used to detect coming out of
"super-standby" mode, and if that is the case, going out of self-refresh mode.

Since we do not support "super-standby" mode, this can be dropped.

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