machines: Drop ast2400/ast2500 layers

The Aspeed layer now supports both chips and the SOC specific layers
do not have any content.  Drop the redundant layers.

Change-Id: I48a813fe4c02b8fc8861c6dd58906ae559c64403
Tested: Built and verified witherspoon and palmetto images
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/meta-msn/conf/bblayers.conf.sample b/meta-msn/conf/bblayers.conf.sample
index 8735273..2dcafab 100644
--- a/meta-msn/conf/bblayers.conf.sample
+++ b/meta-msn/conf/bblayers.conf.sample
@@ -16,7 +16,6 @@
   ##OEROOT##/import-layers/meta-virtualization \
   ##OEROOT##/meta-phosphor \
   ##OEROOT##/meta-openbmc-bsp/meta-aspeed \
-  ##OEROOT##/meta-openbmc-bsp/meta-aspeed/meta-ast2500 \
   ##OEROOT##/meta-openbmc-machines/meta-x86 \
   ##OEROOT##/meta-openbmc-machines/meta-x86/meta-mellanox \
   ##OEROOT##/meta-openbmc-machines/meta-x86/meta-mellanox/meta-msn \
@@ -32,7 +31,6 @@
   ##OEROOT##/import-layers/meta-virtualization \
   ##OEROOT##/meta-phosphor \
   ##OEROOT##/meta-openbmc-bsp/meta-aspeed \
-  ##OEROOT##/meta-openbmc-bsp/meta-aspeed/meta-ast2500 \
   ##OEROOT##/meta-openbmc-machines/meta-x86 \
   ##OEROOT##/meta-openbmc-machines/meta-x86/meta-mellanox \
   ##OEROOT##/meta-openbmc-machines/meta-x86/meta-mellanox/meta-msn \