image_types_phosphor: Adding the extended version in MANIFEST

This patch will add the "ExtendedVersion" field in manifest file.

Note the extended version is typically set in the
openbmc/meta-*/meta-MACHINE/conf/local.conf.sample file
(This is where TEMPLATECONF points to.) by "EXTENDED_VERSION"
variable.

Signed-off-by: Chanh Nguyen <chanh@amperemail.onmicrosoft.com>
Change-Id: I071448badd3b3f56e7d771af0a058bb58db04511
diff --git a/meta-phosphor/classes/image_types_phosphor.bbclass b/meta-phosphor/classes/image_types_phosphor.bbclass
index fa5d319..1ec8706 100644
--- a/meta-phosphor/classes/image_types_phosphor.bbclass
+++ b/meta-phosphor/classes/image_types_phosphor.bbclass
@@ -501,9 +501,11 @@
     purpose = d.getVar('VERSION_PURPOSE', True)
     version = do_get_version(d)
     target_machine = d.getVar('MACHINE', True)
+    extended_version = (d.getVar('EXTENDED_VERSION', True) or "")
     with open('MANIFEST', 'w') as fd:
         fd.write('purpose={}\n'.format(purpose))
         fd.write('version={}\n'.format(version.strip('"')))
+        fd.write('ExtendedVersion={}\n'.format(extended_version))
         fd.write('KeyType={}\n'.format(get_pubkey_type(d)))
         fd.write('HashType=RSA-SHA256\n')
         fd.write('MachineName={}\n'.format(target_machine))