BACKPORT: ext4: Only advertise encrypted_casefold when encryption and unicode are enabled

[ Upstream commit e71f99f2dfb45f4e7203a0732e85f71ef1d04dab ]

Encrypted casefolding is only supported when both encryption and
casefolding are both enabled in the config.

Fixes: 471fbbea7ff7 ("ext4: handle casefolding with encryption")
Cc: stable@vger.kernel.org # 5.13+
Signed-off-by: Daniel Rosenberg <drosen@google.com>
Link: https://lore.kernel.org/r/20210603094849.314342-1-drosen@google.com


Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Change-Id: I4655b3aab60006ea03fb3454a0a833634546373b