MIPS: MIPS32r1: Add optimization for ITransform

Change-Id: Ie4c8b9bc3a7826bd443cdebf05386786fafe8c56
diff --git a/makefile.unix b/makefile.unix
index 30b96cc..92654be 100644
--- a/makefile.unix
+++ b/makefile.unix
@@ -119,6 +119,7 @@
 
 DSP_ENC_OBJS = \
     src/dsp/enc.o \
+    src/dsp/enc_mips32.o \
     src/dsp/enc_neon.o \
     src/dsp/enc_sse2.o \