Add RS math functions for F16.

Bug: 23536224
Bug: 26099914

Change-Id: I8606cb7433b344817970ca7d7995a1b76a88e7af
diff --git a/api/rs_convert.spec b/api/rs_convert.spec
index 810ac76..9b53777 100644
--- a/api/rs_convert.spec
+++ b/api/rs_convert.spec
@@ -73,6 +73,28 @@
 arg: #2#1 v, compatible(#3)
 end:
 
+function: convert_#3#1
+version: UNRELEASED
+attrib: const
+w: 2, 3, 4
+t: f16
+t: u8, u16, u32, u64, i8, i16, i32, i64, f32, f64
+ret: #3#1
+arg: #2#1 v, compatible(#3)
+test: none
+end:
+
+function: convert_#3#1
+version: UNRELEASED
+attrib: const
+w: 2, 3, 4
+t: u8, u16, u32, u64, i8, i16, i32, i64, f32, f64
+t: f16
+ret: #3#1
+arg: #2#1 v, compatible(#3)
+test: none
+end:
+
 function: rsPackColorTo8888
 attrib: const
 ret: uchar4