lantiq: add additional caldata offsets

lantiq: add additional caldata offsets

It was reported the AVM FritzBox 7430 has different offsets for the
caldata depending on the device.

Whether this is due to custom bad-block handling or up to the installed
bootloader-version is unknown.

Try both known caldata offsets like it is already done for the ipq40xx
NAND based models. Use the same approach for the FritzBox 7412. While it
is currently unknown, whether it is affected, applying the same logic
has no downsides.

Signed-off-by: David Bauer <mail@david-bauer.net>