sunxi: Use a common CONFIG_SYS_PROMPT
The CPU info is already logged during boot e.g.
CPU: Allwinner A20 (SUN7I)
so the prompt is just one more thing to change for each new SoC, just makes it
"sunxi#" instead.
Signed-off-by: Ian Campbell <ijc@hellion.org.uk>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>