sunxi: Add CONFIG_MACH_TYPE defines to sun4i, sun5i and sun7i

sunxi: Add CONFIG_MACH_TYPE defines to sun4i, sun5i and sun7i

Many people are still using old linux-sunxi-3.4 kernels on sunxi devices,
adding the proper MACH_TYPE defines for this allows people to switch to
upstream u-boot, so that we can stop maintaining the linux-sunxi u-boot fork.

These machine-ids are all properly registered at:

http://www.arm.linux.org.uk/developer/machines/

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Ian Campbell <ijc@hellion.org.uk>