ppc: move more files to hw/ppc

These sPAPR files do not implement devices, move them over.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

hw/ppc/Makefile.objs

 # PREP target
 obj-y += mc146818rtc.o
 # IBM pSeries (sPAPR)
-obj-$(CONFIG_PSERIES) += spapr_hcall.o spapr_rtas.o
 obj-$(CONFIG_PSERIES) += spapr_vty.o spapr_llan.o spapr_vscsi.o
-obj-$(CONFIG_PSERIES) += spapr_pci.o pci/pci-hotplug.o spapr_iommu.o
-obj-$(CONFIG_PSERIES) += spapr_events.o spapr_nvram.o
+obj-$(CONFIG_PSERIES) += spapr_pci.o pci/pci-hotplug.o
+obj-$(CONFIG_PSERIES) += spapr_nvram.o
 # PowerPC 4xx boards
 obj-y += ppc4xx_pci.o
 # PowerPC OpenPIC
@@ -18,7 +17,8 @@ obj-y := $(addprefix ../,$(obj-y))
 # shared objects
 obj-y += ppc.o ppc_booke.o
 # IBM pSeries (sPAPR)
-obj-$(CONFIG_PSERIES) += spapr.o xics.o spapr_vio.o
+obj-$(CONFIG_PSERIES) += spapr.o xics.o spapr_vio.o spapr_events.o
+obj-$(CONFIG_PSERIES) += spapr_hcall.o spapr_iommu.o spapr_rtas.o
 # PowerPC 4xx boards
 obj-y += ppc405_boards.o ppc4xx_devs.o ppc405_uc.o ppc440_bamboo.o
 # PReP