use me_cleaner from coreboot instead of upstream

coreboot closely matches upstream, whose current release
is version 1.2 from 2018, and coreboot has not changed it
in any meaningful way.

the upstream did add patches since, but they are documentation
patches only.

this means: we do not need to use the upstream version

Signed-off-by: Leah Rowe <leah@libreboot.org>

config/git/me_cleaner

@@ -1,5 +0,0 @@
-{me_cleaner}{
-	rev: 43612a630c79f3bc6f2653bfe90dfe0b7b137e08
-	loc: me_cleaner
-	url: https://github.com/corna/me_cleaner.git
-}