For spelling's sake, rename Python routine "setup_revisons" to
"setup_revisions."
(Bitbake rev: 4df59b027c02ef39d72476251ccd3fd62fc20bf6)
Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>