Current shdmac can support SDHI DMAC on r8a7740.
This support reduce CPU duty when SDHI access.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> Acked-by: Magnus Damm <damm@opensource.se> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>