blk-crypto: export wrapped key functions

Export blk_crypto_derive_sw_secret(), blk_crypto_import_key(),
blk_crypto_generate_key(), and blk_crypto_prepare_key() so that they can
be used by device-mapper when passing through wrapped key support.

Signed-off-by: Eric Biggers <[e-mail]>
Signed-off-by: Mikulas Patocka <[e-mail]>

block/blk-crypto-profile.c

···
 	blk_crypto_hw_exit(profile);
 	return err;
 }
+EXPORT_SYMBOL_GPL(blk_crypto_derive_sw_secret);
 
 int blk_crypto_import_key(struct blk_crypto_profile *profile,
 			  const u8 *raw_key, size_t raw_key_size,
···
 	blk_crypto_hw_exit(profile);
 	return ret;
 }
+EXPORT_SYMBOL_GPL(blk_crypto_import_key);
 
 int blk_crypto_generate_key(struct blk_crypto_profile *profile,
 			    u8 lt_key[BLK_CRYPTO_MAX_HW_WRAPPED_KEY_SIZE])
···
 	blk_crypto_hw_exit(profile);
 	return ret;
 }
+EXPORT_SYMBOL_GPL(blk_crypto_generate_key);
 
 int blk_crypto_prepare_key(struct blk_crypto_profile *profile,
 			   const u8 *lt_key, size_t lt_key_size,
···
 	blk_crypto_hw_exit(profile);
 	return ret;
 }
+EXPORT_SYMBOL_GPL(blk_crypto_prepare_key);
 
 /**
  * blk_crypto_intersect_capabilities() - restrict supported crypto capabilities