Fix 'make clean' and .gitignore for firmware/ directory.

Provide a .gitignore file, and fix a typo which prevented some of the
generated binary files from being removed on 'make clean'.

Signed-off-by: David Woodhouse <[email protected]>
Reported-and-tested-by: Alexey Dobriyan <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
2 files changed