mmc: tmio, renesas_sdhi: move Renesas-specific DMA data to renesas_sdhi.h

struct tmio_mmc_host has "dma_dataend" and "dma_complete", but in fact,
they are Renesas private data.  Move them to renesas_sdhi.h

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>