meta-ampere: mtmitchell: state: remove redundant build option

In the commit 16bb75ab on the openbmc repo, it disables warm-reboot by
default, we don't have to disable it again.

Tested:
       1. Request power reset Host.
          $ipmitool power reset
       2. Reboot target is called.

Change-Id: Ie1ed12709c200d358ae4e93e55565ebd1ea68c4f
Signed-off-by: Thang Tran <thuutran@amperecomputing.com>
diff --git a/meta-ampere/meta-mitchell/recipes-phosphor/state/phosphor-state-manager_%.bbappend b/meta-ampere/meta-mitchell/recipes-phosphor/state/phosphor-state-manager_%.bbappend
deleted file mode 100644
index 164614a..0000000
--- a/meta-ampere/meta-mitchell/recipes-phosphor/state/phosphor-state-manager_%.bbappend
+++ /dev/null
@@ -1,5 +0,0 @@
-FILESEXTRAPATHS:prepend := "${THISDIR}/${PN}:"
-
-EXTRA_OEMESON:append = " \
-                         -Dwarm-reboot=disabled \
-                       "