Organize OpenPOWER BMC support as features

Add OBMC_MACHINE_FEATURES for OpenPOWER support under openpower.inc.
Select OpenPOWER features in the POWER machines' DISTRO_FEATURES so that
the features are built.

The features are:
  obmc-openpower for required base support
  obmc-openpower-extra for non-essential tools
  obmc-openpower-legacy for deprecated packages like org.openbmc and
    skeleton packages

Part of openbmc/openbmc#2652.

Change-Id: Ib9f44a0c2e243eebb6594de6554cdc3fa0d076af
Signed-off-by: Xo Wang <xow@google.com>
diff --git a/meta-openbmc-machines/meta-openpower/meta-ibm/meta-romulus/conf/machine/romulus.conf b/meta-openbmc-machines/meta-openpower/meta-ibm/meta-romulus/conf/machine/romulus.conf
index e5e98e9..06572a8 100644
--- a/meta-openbmc-machines/meta-openpower/meta-ibm/meta-romulus/conf/machine/romulus.conf
+++ b/meta-openbmc-machines/meta-openpower/meta-ibm/meta-romulus/conf/machine/romulus.conf
@@ -13,5 +13,11 @@
 PHOSPHOR_MRW_URI = "git://github.com/open-power/romulus-xml"
 PHOSPHOR_MRW_REV = "14b471fbf37f5fb60261de001df83caf5f96d81f"
 
+DISTRO_FEATURES_append = "\
+        obmc-openpower \
+        obmc-openpower-extra \
+        obmc-openpower-legacy \
+        "
+
 PREFERRED_PROVIDER_virtual/phosphor-ipmi-fru-inventory = "romulus-ipmi-inventory-map-native"
-PREFERRED_PROVIDER_virtual/phosphor-led-manager-config-native = "romulus-led-manager-config-native"
\ No newline at end of file
+PREFERRED_PROVIDER_virtual/phosphor-led-manager-config-native = "romulus-led-manager-config-native"