Add hch to .get_maintainer.ignore

While the idea behind get_maintainer seems highly useful it's
unfortunately way to trigger happy to grab people that once had a few
commits to files.  For someone like me who does a lot of tree-wide API
work that leads to an incredible amount of Cc spam.

Signed-off-by: Christoph Hellwig <[email protected]>
Cc: Joe Perches <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

Author: Christoph Hellwig

.get_maintainer.ignore

@@ -0,0 +1 @@
+Christoph Hellwig <hch@lst.de>