buildman: fix boards.cfg parsing

Commit 27af930e9a5c91365ca639ada580b338eabe4989 changed the boards.cfg format
but missed to change the parsing in buildman.

This patch changes c'tor of Board class to the new sequence, but omits
maintainer field.

Signed-off-by: Andreas Bießmann <andreas.devel@googlemail.com>
1 file changed