GFS2: Switch fiemap implementation to use iomap

This patch switches GFS2's implementation of fiemap from the old
block_map code to the new iomap interface.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
diff --git a/fs/gfs2/Kconfig b/fs/gfs2/Kconfig
index 90c6a8f..43c827a 100644
--- a/fs/gfs2/Kconfig
+++ b/fs/gfs2/Kconfig
@@ -4,6 +4,7 @@
 	select FS_POSIX_ACL
 	select CRC32
 	select QUOTACTL
+	select FS_IOMAP
 	help
 	  A cluster filesystem.