firmware: Fix a typo in fallback-mechanisms.rst

This patch fix a spelling typo found in fallback-mechanisms.rst

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Luis R. Rodriguez <mcgrof@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 file changed