lseek must return the current file position. Previously, the littlefs
version always returned 0, which broke terrain I/O as it checks that the
position returned is the one it seeked to. Fix to return the current
position, which is correctly returned from littlefs.
This problem was originally and incorrectly diagnosed as an issue with
littlefs seeking past the end of the file, but this functionality works
fine and fixing the incorrect return completely fixes terrain.
Terrain functionality was verified using `TERRAIN_DEBUG` on
KakuteH7Mini-Nand running sim on HW. Terrain data is correctly
downloaded from the GCS and loaded from the filesystem after reboot.
optimize configured defaults on littlefs and address review comments
support lseek() in littlefs in a way that enables terrain to work
rename file and directory structures in littlefs
code in littlefs glue should be C++ rather than C
check for strdup failure on littlefs
use correct read status for nor flash
implement format on littlefs
optimize device calls in littlefs flash usage
check for fileops allowed in littlefs
littlefs optimization and support for mtime
