sunxi: Store the device tree name in the SPL header

sunxi: Store the device tree name in the SPL header

This patch updates the mksunxiboot tool to optionally add
the default device tree name string to the SPL header. This
information can be used by the firmware upgrade tools to
protect users from harming themselves by trying to upgrade
to an incompatible bootloader.

The primary use case here is a non-removable bootable media
(such as NAND, eMMC or SPI flash), which already may have
a properly working, but a little bit outdated bootloader
installed. For example, the user may download or build a
new U-Boot image for "Cubieboard", and then attemept to
install it on a "Cubieboard2" hardware by mistake as a
replacement for the already existing bootloader. If this
happens, the flash programming tool can identify this
problem and warn the user.

The size of the SPL header is also increased from 64 bytes
to 96 bytes to provide enough space for the device tree name
string.
[Andre: split patch to remove OF_LIST hash feature]

Signed-off-by: Siarhei Siamashka <siarhei.siamashka@gmail.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>