Add rsDebug for half

http://b/27556050

Update API generator specification and generated rs_debug.rsh file.

Change-Id: Icc731e16c142720d5cca5523a904d800f67f6253
diff --git a/api/rs_debug.spec b/api/rs_debug.spec
index dcafe20..35d9265 100644
--- a/api/rs_debug.spec
+++ b/api/rs_debug.spec
@@ -67,6 +67,15 @@
 end:
 
 function: rsDebug
+version: 24
+w: 1, 2, 3, 4
+ret: void
+arg: const char* message
+arg: half#1 a
+test: none
+end:
+
+function: rsDebug
 version: 17
 w: 1, 2, 3, 4
 t: i8, u8, i16, u16