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>
diff --git a/drivers/mmc/Kconfig b/drivers/mmc/Kconfig
index bb38787..8f0df56 100644
--- a/drivers/mmc/Kconfig
+++ b/drivers/mmc/Kconfig
@@ -358,6 +358,7 @@
 	depends on ARCH_RMOBILE
 	depends on BLK && DM_MMC
 	depends on OF_CONTROL
+	select BOUNCE_BUFFER
 	help
 	  This selects support for the Matsushita SD/MMC Host Controller on
 	  Renesas R-Car SoCs.