PPC: Add new target config for pseries

We only support -M pseries when certain prerequisites are met, such
as a PPC64 guest and libfdt. To only gather these requirements in
a single place, this patch introduces a new CONFIG_PSERIES variable
that gets set when all prerequisites are met.
Signed-off-by: NAlexander Graf <agraf@suse.de>

Makefile.target

@@ -239,10 +239,8 @@ obj-ppc-y += ppc_oldworld.o
 # NewWorld PowerMac
 obj-ppc-y += ppc_newworld.o
 # IBM pSeries (sPAPR)
-ifeq ($(CONFIG_FDT)$(TARGET_PPC64),yy)
-obj-ppc-y += spapr.o spapr_hcall.o spapr_rtas.o spapr_vio.o
-obj-ppc-y += xics.o spapr_vty.o spapr_llan.o spapr_vscsi.o
-endif
+obj-ppc-$(CONFIG_PSERIES) += spapr.o spapr_hcall.o spapr_rtas.o spapr_vio.o
+obj-ppc-$(CONFIG_PSERIES) += xics.o spapr_vty.o spapr_llan.o spapr_vscsi.o
 # PowerPC 4xx boards
 obj-ppc-y += ppc4xx_devs.o ppc4xx_pci.o ppc405_uc.o ppc405_boards.o
 obj-ppc-y += ppc440.o ppc440_bamboo.o

configure

@@ -3389,6 +3389,9 @@ case "$target_arch2" in
       fi
     fi
 esac
+if test "$target_arch2" = "ppc64" -a "$fdt" = "yes"; then
+  echo "CONFIG_PSERIES=y" >> $config_target_mak
+fi
 if test "$target_bigendian" = "yes" ; then
   echo "TARGET_WORDS_BIGENDIAN=y" >> $config_target_mak
 fi