spi: rspi: Configure DMA slave bus width to 8 bit
spi: rspi: Configure DMA slave bus width to 8 bit

The new Renesas R-Car Gen2 DMA Controller driver (rcar-dmac) requires
explicit configuration of the DMA slave bus width.
Hardcode the DMA transfer size to 1 byte for both directions, as that's
the only supported configuration (16-bit DMA support was removed in
commit 9c5de2c1754c2bb3c69c4d7bf0d0edc0a61d8232 ("spi: rspi: Remove
unused 16-bit DMA support")).

Signed-off-by: Geert Uytterhoeven <a1ff81395f7e6bf5b509fe9aab06bf3419493e1d@glider.be>
Signed-off-by: Mark Brown <b51b9a92386687a9ac927cebfa0f978adeb8cea5@linaro.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs