meta-ibm: Remove tacoma-specific options from witherspoon

The KCS device is only used on Tacoma, so move them out to their own
file.

Signed-off-by: Joel Stanley <joel@jms.id.au>
Change-Id: I157a597c753440220b1e92b60191a0c5191e4aec
diff --git a/meta-ibm/recipes-kernel/linux/linux-aspeed_%.bbappend b/meta-ibm/recipes-kernel/linux/linux-aspeed_%.bbappend
index 758494e..54f4f9b 100644
--- a/meta-ibm/recipes-kernel/linux/linux-aspeed_%.bbappend
+++ b/meta-ibm/recipes-kernel/linux/linux-aspeed_%.bbappend
@@ -1,3 +1,4 @@
 FILESEXTRAPATHS:prepend := "${THISDIR}/${PN}:"
 SRC_URI:append:ibm-ac-server = " file://witherspoon.cfg"
+SRC_URI:append:witherspoon-tacoma = " file://witherspoon-tacoma.cfg"
 SRC_URI:append:p10bmc = " file://p10bmc.cfg"