Drop a redundant "mmp_tdma:" from some error messages. The dev_err()
appends mostly the same thing for us:

  [  120.756530] mmp-tdma d42a0800.adma: mmp_tdma: unknown burst size.
Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Link: https://lore.kernel.org/r/20200419164912.670973-3-lkundrak@v3.skSigned-off-by: Vinod Koul <vkoul@kernel.org>