Add a flag for SDHI1 to enable SDIO IRQ, and remove DMA Engine
slave id:s to disable DMA as a workaround.

Tested on sh73a0/AG5EVM with a BCM4318-based SDIO card.
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>