BMC: Update u-boot environment variables.

- Create a service file that can update the u-boot variables
  (kernelname, root and ubiblock) to point to a different
  BMC version.
- This service file will be called by the BMC ItemUpdater
  if a user sets BMC version priority to the lowest value.

Change-Id: Ic83c7e7a1c36eefc6c0b1b12b2077f5a866db36c
Signed-off-by: Saqib Khan <khansa@us.ibm.com>
diff --git a/common/recipes-phosphor/flash/phosphor-software-manager/obmc-flash-bmc-updateubootvars@.service b/common/recipes-phosphor/flash/phosphor-software-manager/obmc-flash-bmc-updateubootvars@.service
new file mode 100644
index 0000000..bab0b02
--- /dev/null
+++ b/common/recipes-phosphor/flash/phosphor-software-manager/obmc-flash-bmc-updateubootvars@.service
@@ -0,0 +1,8 @@
+[Unit]
+Description= Updates the u-boot variable to point BMC version to %I
+
+[Service]
+Type=oneshot
+RemainAfterExit=no
+ExecStart=/usr/bin/env obmc-flash-bmc updateubootvars %i
+SyslogIdentifier=obmc-flash-bmc