Remove documentation as swabber was removed from oe-core with
this commit: commit a7ddbea345c90646e6b9ddb89f768865caffdf07
(From yocto-docs rev: f3c462b2c6aa20de53c77e5d93cf397ae36cb2bb)
Signed-off-by: Scott Rifenbark <srifenbark@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>