FlashFS: fix formatting with multiple instances

The old format command took a (0) in for no reason which
because the uintptr_t to the file system and obviously
results in an error erasing flash.
Merge pull request #474 from peabody124/flashfs_format_fix

FlashFS: fix formatting with multiple instances
Merge pull request #473 from solidgoldbomb/math-unit-tests

Math unit tests
sin_lookup: fix typo in init function name
sin_lookup: clean up widely scoped and unneeded includes

Including files unnecessarily makes it harder to build these
files for unit tests.
ut sin_lookup: add basic unit test for sin_lookup.c

Functions are validated against host's sinf/cosf implementations.

Only the (default) FLASH_TABLE variant is currently tested.