appsbl: qseecom_lk: Add stub for cmnlib64 loading

Add stub code for cmnlib64 loading, OEM's that load
64-bit TA's will enable the feature flag and compile.
Changed Req and Rsp buffer to be different rather than
use the same buffer.

Change-Id: I05ada7f2e6cb3cdd8ce07cbb41a3930f1c3fe189
diff --git a/project/msm8996.mk b/project/msm8996.mk
index 4c5d6a1..5229e83 100644
--- a/project/msm8996.mk
+++ b/project/msm8996.mk
@@ -41,6 +41,8 @@
 DEFINES += USE_BOOTDEV_CMDLINE=1
 DEFINES += USE_RPMB_FOR_DEVINFO=1
 DEFINES += ENABLE_WBC=1
+#Enable below flag to compile cmnlib64
+#DEFINES += ENABLE_CMNLIB64_LOADING=1
 
 #Disable thumb mode
 ENABLE_THUMB := false