ARM: shmobile: use common DMAEngine definitions on sh73a0

This patch switch over to use common DMAEngine definitions,
and reduced a waste of code.

It is easy to understand if sh_dmae_pdata / sh_dmae_slave_config
settings are used defined value instead of direct value.

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>