added ir code sad u8

Change-Id: Ie0d454b3bb9a6c9a028c091ad3aa969719b02cc9

hipamd/src/hip_ir.ll

@@ -171,4 +171,9 @@ define i32 @__hip_hc_ir_usad_int(i32 %a, i32 %b, i32 %c) #1 {
   ret i32 %1
 }
 
+define i32 @__hip_hc_ir_sadu8_int(i32 %a, i32 %b, i32 %c) #1 {
+  %1 = tail call i32 asm sideeffect "v_sad_u8 $0, $1, $2 $3","=v,v,v,v"(i32 %a, i32 %b, i32 %c)
+  ret i32 %1
+}
+
 attributes #1 = { alwaysinline nounwind }