meta-ibm: Enable the proper power button profile

Tell phosphor-buttons the proper power button profile to use for IBM
p10bmc systems so it meets IBM's requirements.

Signed-off-by: Matt Spinler <spinler@us.ibm.com>
Change-Id: I48337c9b2d31c47c9e3aa0bfaa5f8ebda80e8577
diff --git a/meta-ibm/recipes-phosphor/chassis/obmc-phosphor-buttons_%.bbappend b/meta-ibm/recipes-phosphor/chassis/obmc-phosphor-buttons_%.bbappend
new file mode 100644
index 0000000..b7b28f8
--- /dev/null
+++ b/meta-ibm/recipes-phosphor/chassis/obmc-phosphor-buttons_%.bbappend
@@ -0,0 +1 @@
+EXTRA_OEMESON:append:p10bmc = " -Dpower-button-profile=host_then_chassis_poweroff"