Enabling first-boot-set-hostname service on witherspoon

first-boot-set-hostname service will set a unique hostname
to the machine on the very first boot. The idea of this
commit is to enable this service as a part of witherspoon
image.

Tested by:

1. Enable first-boot-set-hostname.service
   - systemctl enable first-boot-set-hostname.service

2. Reboot the machine
   - reboot

Post reboot, hostname will be changed to hostname-serialno

Signed-off-by: asmithakarun <asmithkr@in.ibm.com>
Change-Id: I6625a197879641de5f6975e014928bf45b32bae5
diff --git a/meta-witherspoon/recipes-phosphor/images/obmc-phosphor-image.bbappend b/meta-witherspoon/recipes-phosphor/images/obmc-phosphor-image.bbappend
index aa7e786..7702d99 100644
--- a/meta-witherspoon/recipes-phosphor/images/obmc-phosphor-image.bbappend
+++ b/meta-witherspoon/recipes-phosphor/images/obmc-phosphor-image.bbappend
@@ -1 +1 @@
-OBMC_IMAGE_EXTRA_INSTALL_append = " mboxd max31785-msl phosphor-msl-verify liberation-fonts uart-render-controller first-boot-set-mac"
+OBMC_IMAGE_EXTRA_INSTALL_append = " mboxd max31785-msl phosphor-msl-verify liberation-fonts uart-render-controller first-boot-set-mac first-boot-set-hostname"