ARM: dts: OMAP4: Fix broken pbias device creation

ARM: dts: OMAP4: Fix broken pbias device creation

commit 89a898df87e114952191ab0e061aa18e3c617880 upstream.

commit <7415b0b4c645> ("ARM: dts: omap4: add minimal l4 bus layout
with control module support") moved pbias_regulator dt node
from being a child node of ocp to be the child node of
omap4_padconf_global. After this device for pbias_regulator
is not created.

Fix it by adding "simple-bus" compatible property to
omap4_padconf_global dt node.

Fixes: 7415b0b4c645 ("ARM: dts: omap4: add minimal l4 bus layout
with control module support")

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>