ARM: dts: sunxi: Add regulator-boot-on property to ahci-5v regulator

This avoids it getting briefly turned off between when the regulator getting
registered and the ahci driver turning it back on, thus avoiding the disk
going into emergency head park mode.

Reported-by: Bruno Prémont <bonbons@linux-vserver.org>
Tested-by: Bruno Prémont <bonbons@linux-vserver.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>