dmaengine: Revert "rcar-dmac: use TCRB instead of TCR for residue"

This reverts commit 847449f2

: ("dmaengine: rcar-dmac: use TCRB instead
of TCR for residue") as it breaks small serial console.

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>