openpower-pnor: move options into menu for clarity

Signed-off-by: Stewart Smith <stewart@linux.ibm.com>
diff --git a/openpower/package/openpower-pnor/Config.in b/openpower/package/openpower-pnor/Config.in
index 836ef77..92adf36 100644
--- a/openpower/package/openpower-pnor/Config.in
+++ b/openpower/package/openpower-pnor/Config.in
@@ -16,6 +16,8 @@
         help
             Utilites for building a targeting binary image
 
+menu "OpenPOWER PNOR assembly options"
+
 choice
     prompt "Secure Boot key transition type"
     default BR2_OPENPOWER_SECUREBOOT_NO_KEY_TRANSITION
@@ -159,3 +161,5 @@
 config BR2_BUILD_PNOR_SQUASHFS
         bool "Create a virtual PNOR image along with the standard image"
         default y
+
+endmenu