sh: fix Transfer Size calculation in both DMA drivers

Both the original arch/sh/drivers/dma/dma-sh.c and the new SH dmaengine drivers
do not take into account bits 3:2 of the Transfer Size field in the CHCR
register, besides, bit-field defines set bit 2, but the mask only passes bits
1:0 through. TS_16BLK and TS_32BLK macros are bogus too. This patch fixes all
these issues for sh7722 and sh7724, other CPUs stay unchanged and might need to
be fixed too.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>