ext4: load the crc32c driver if necessary

Obtain a reference to the cryptoapi and crc32c if we mount a
filesystem with metadata checksumming enabled.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/Kconfig b/fs/ext4/Kconfig
index 9ed1bb1..c22f170 100644
--- a/fs/ext4/Kconfig
+++ b/fs/ext4/Kconfig
@@ -2,6 +2,8 @@
 	tristate "The Extended 4 (ext4) filesystem"
 	select JBD2
 	select CRC16
+	select CRYPTO
+	select CRYPTO_CRC32C
 	help
 	  This is the next generation of the ext3 filesystem.