mmc: tmio: sdhi: Use bounce buffer to avoid DMA limitations

The R-Car SDHI DMA controller has various restrictions. To work around
those restrictions without falling back to PIO, implement bounce buffer
with custom alignment check function which tests for those limitations.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Peng Fan <peng.fan@nxp.com>
Cc: Simon Glass <sjg@chromium.org>
Cc: Tom Rini <trini@konsulko.com>
2 files changed