Restrict root user password to obmc-phosphor-image

Restrict root user password to obmc-phosphor-image image recipe.

(From meta-phosphor rev: 2ce22326700e4ea1d382081b980bd51447700de6)

Change-Id: Icaab0a1017e8abe54dce0ad5f0ac091f6e2045eb
Signed-off-by: Richard Marian Thomaiyar <richard.marian.thomaiyar@linux.intel.com>
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/meta-phosphor/conf/distro/include/phosphor-defaults.inc b/meta-phosphor/conf/distro/include/phosphor-defaults.inc
index 5659215..bac3ad1 100644
--- a/meta-phosphor/conf/distro/include/phosphor-defaults.inc
+++ b/meta-phosphor/conf/distro/include/phosphor-defaults.inc
@@ -248,6 +248,6 @@
 # Set the root password to '0penBmc'
 inherit extrausers
 
-EXTRA_USERS_PARAMS = " \
+EXTRA_USERS_PARAMS_pn-obmc-phosphor-image = " \
   usermod -p '\$1\$UGMqyqdG\$FZiylVFmRRfl9Z0Ue8G7e/' root; \
   "