add s4 s905w2 bl40 signed binary.

Change-Id: I2547b0195defe1c3552fa133f3b962dcd15d45cc
diff --git a/s4/s905w2/blob-bl40.bin.signed b/s4/s905w2/blob-bl40.bin.signed
index 3224746..be93c0c 100644
--- a/s4/s905w2/blob-bl40.bin.signed
+++ b/s4/s905w2/blob-bl40.bin.signed
Binary files differ