meta-openpower: Create new virtual-pnor distro feature

Currently the virtual pnor features are conditioned on the ubi
distro feature, but there are cases where a system running on
an emmc for example is not using ubi but would like to use
virtual pnor. Therefore create a separate distro feature to
enable it, and add it to the ubi distro feature to ensure that
any system that includes ubi doesn't have to remember to add
this new virtual pnor distro feature.

Tested: "bitbake -e" shows DISTRO_FEATURES="... openpower-virtual-pnor openpower-ubi-fs"

(From meta-openpower rev: c835070e9e05a71e1b8bc1a06a61d0d28e5d29f4)

Change-Id: If6951ea06effbfa545697ecd564be5762b2bfb2b
Signed-off-by: Adriana Kobylak <anoo@us.ibm.com>
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/meta-openpower/conf/distro/include/openpower-ubi.inc b/meta-openpower/conf/distro/include/openpower-ubi.inc
index cb488c8..95355b8 100644
--- a/meta-openpower/conf/distro/include/openpower-ubi.inc
+++ b/meta-openpower/conf/distro/include/openpower-ubi.inc
@@ -1,2 +1,4 @@
+require conf/distro/include/openpower-virtual-pnor.inc
+
 DISTRO_FEATURES += "openpower-ubi-fs"
 DISTROOVERRIDES .= ":df-openpower-ubi-fs"