ARM: omap2plus_defconfig: Enable simple-pm-bus

We can use simple-pm-bus instead of simple-bus, let's enable it to allow
configuring it in dts files for using things like genpd.
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/configs/omap2plus_defconfig

@@ -130,6 +130,7 @@ CONFIG_PCI_EPF_TEST=m
 CONFIG_DEVTMPFS=y
 CONFIG_DEVTMPFS_MOUNT=y
 CONFIG_OMAP_OCP2SCP=y
+CONFIG_SIMPLE_PM_BUS=y
 CONFIG_CONNECTOR=m
 CONFIG_MTD=y
 CONFIG_MTD_CMDLINE_PARTS=y