There is a copy and paste bug so we accidentally use the RX_ shift when
we're in TX_ mode.

Fixes: bb8b2062 ("fsl/qe: setup clock source for TDM mode")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Zhao Qiang <qiang.zhao@nxp.com>
Signed-off-by: Li Yang <leoyang.li@nxp.com>
(cherry picked from commit 3cb31b634052ed458922e0c8e2b4b093d7fb60b9)
Signed-off-by: Olof Johansson <olof@lixom.net>