meta-facebook: remove excess override syntaxes

When a bbappend file is already in a meta-machine layer, there is no
reason for extra ":machine" override syntax usage.  Remove them all.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I610e72633adb5bc36b63fe2b727e394c61070185
diff --git a/meta-facebook/meta-greatlakes/recipes-phosphor/fans/phosphor-fan_%.bbappend b/meta-facebook/meta-greatlakes/recipes-phosphor/fans/phosphor-fan_%.bbappend
index 0099418..4c3928e 100644
--- a/meta-facebook/meta-greatlakes/recipes-phosphor/fans/phosphor-fan_%.bbappend
+++ b/meta-facebook/meta-greatlakes/recipes-phosphor/fans/phosphor-fan_%.bbappend
@@ -1 +1 @@
-EXTRA_OEMESON:greatlakes = "-Duse-host-power-state=enabled -Dsensor-monitor-hard-shutdown-delay=0"
+EXTRA_OEMESON = "-Duse-host-power-state=enabled -Dsensor-monitor-hard-shutdown-delay=0"