ARM: shmobile: r8a7740: Add A4SU pm domain support

Add support for the A4SU power domain.
This domain contains the USBPHY hardware block, which is currently not
used by any driver.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NSimon Horman <horms+renesas@verge.net.au>

arch/arm/mach-shmobile/pm-r8a7740.c

@@ -75,6 +75,9 @@ static struct rmobile_pm_domain r8a7740_pm_domains[] = {
 	}, {
 		.genpd.name	= "A3SG",
 		.bit_shift	= 13,
+	}, {
+		.genpd.name	= "A4SU",
+		.bit_shift	= 20,
 	},
 };