drm/amd/display: Fix message for encryption

-msg_in is not needed for enabling encryption.
-Use hdcp2_set_encryption instead of hdcp1_enable_encryption for hdcp2.2

Signed-off-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>