Current shdmac can support FSI DMAC on r8a7740.
This support reduce CPU duty when sound was playback.

This patch is based on v1.0 manual
Signed-off-by: NKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: NMagnus Damm <damm@opensource.se>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>