meta-bletchley: chassis: set OBMC_CHASSIS_INSTANCES

Bletchley has the primary sled and N secondary slots, each of which
should be considered a 'chassis' from a power control perspective.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I9f948c31c720e13c72a9f4d68500fd8990a4849b
diff --git a/meta-facebook/meta-bletchley/conf/machine/bletchley.conf b/meta-facebook/meta-bletchley/conf/machine/bletchley.conf
index c0df356..1d1a5b8 100644
--- a/meta-facebook/meta-bletchley/conf/machine/bletchley.conf
+++ b/meta-facebook/meta-bletchley/conf/machine/bletchley.conf
@@ -16,4 +16,5 @@
 PREFERRED_PROVIDER_virtual/phosphor-led-manager-config-native = "bletchley-led-manager-config-native"
 
 OBMC_HOST_INSTANCES = "1 2 3 4 5 6"
-
+# Primary chassis as Sled plus secondary chassis in N slots.
+OBMC_CHASSIS_INSTANCES = "0 ${OBMC_HOST_INSTANCES}"