Several devices with tplink-safeloader contain default values (0x0)
for TPLINK_HWID and TPLINK_HWREV in their device definitions.
Move those to common tplink-safeloader definition so they do not
have to be repeated each time.
While at it, set default value for tplink-v1 and tplink-v2 as well.
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>