Remove largely unmaintained Mihawk

A fork of it is maintained but its upstream layer has largely been
unmaintained.
No future products are planned to be based on this layer.
Mihawk is similar to Witherspoon.

Signed-off-by: Myung Bae <myungbae@us.ibm.com>
Change-Id: I82f7d777b78cd126237d51e42f1e11abdf80ae68
diff --git a/meta-ibm/recipes-phosphor/flash/openpower-software-manager_%.bbappend b/meta-ibm/recipes-phosphor/flash/openpower-software-manager_%.bbappend
index 2d9c096..38b5e47 100644
--- a/meta-ibm/recipes-phosphor/flash/openpower-software-manager_%.bbappend
+++ b/meta-ibm/recipes-phosphor/flash/openpower-software-manager_%.bbappend
@@ -1,2 +1 @@
-PACKAGECONFIG:append:ibm-ac-server = " verify_pnor_signature"
-PACKAGECONFIG:append:mihawk = " verify_pnor_signature"
+PACKAGECONFIG:append:ibm-ac-server = " verify_pnor_signature"
\ No newline at end of file