NKelias

Add additional memory page for OTP slots

1

This reduces the size of the OTP global config field to 16 Bytes to make room for all 19 OTP slots. fixes #91

Persistent user data (OTP data, Unix Timestamp, etc.) is currently written to hard-coded Flash addresses by the firmware. These portions of memory should also be reserved in the linker script...

Current implementation relies on user input to be null-terminated. This should be changed to either use `strnlen` or a constant length implementation. https://github.com/Nitrokey/nitrokey-storage-firmware/blob/2d3f4a9f2c8dc1d1d119f8ceed0fc886aff7898d/src/USER_INTERFACE/html_io.c#L773