firmware-utils: tplink-safeloader: improve soft-version customisation

firmware-utils: tplink-safeloader: improve soft-version customisation

Some devices using the safeloader firmware format require a minimum or
specific version to be set in the soft-version metadata partition.
Currently only custom text values can be provided, but not all device
firmware support this format.

Modify the device info struct to allow for more well-defined types of
soft-version overwrites, and provide a few macros for easy value
initialisation. Requires all existing values to be updated to match the
new structure.

Signed-off-by: Sander Vanheule <sander@svanheule.net>
[Adapt TL-WA1201-V2 entry too]
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>