OMAP3: PM: Emu_pwrdm is switched off by hardware even when sdti is in use

Using sdti doesn't keep emu_pwrdm on if hardware supervised pwrdm
transitions are used. This causes sdti stop to work when power
management is initialized and hardware supervised pwrdm control is
enabled. This patch disables hardware supervised pwrdm control for
emu_pwrdm. Now emu_pwrdm is switched off on boot by software when it
is not used.

Signed-off-by: Jouni Hogander <jouni.hogander@nokia.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>