ARM: shmobile: r8a7740: add A4LC pm domain support

This patch adds basic A4LC pm domain support.
Now, below devices can be controled by PM

MERAM, LCDC, VOU, ICBS, SDENC-Link

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>