msm: synx: build script as DLKM for Vendor SI

added mk and Kbuild script to support building synx driver as external module for Vendor SI

Change-Id: Ib66325d115ca46e6b61de1e168e85d09419f73e2
Signed-off-by: NITIN LAXMIDAS NAIK <quic_nitinlax@quicinc.com>

Android.bp

@@ -0,0 +1,5 @@
+cc_library_headers {
+    name: "qti_synx_kernel_headers",
+    export_include_dirs: ["include/uapi/synx/media"],
+    vendor_available: true
+}