Fix compilation of jpeg2000dsp when disabling the encoder.

Signed-off-by: James Almer <jamrial@gmail.com>

libavcodec/Makefile

@@ -275,8 +275,8 @@ OBJS-$(CONFIG_INTERPLAY_DPCM_DECODER)  += dpcm.o
 OBJS-$(CONFIG_INTERPLAY_VIDEO_DECODER) += interplayvideo.o
 OBJS-$(CONFIG_JACOSUB_DECODER)         += jacosubdec.o ass.o
 OBJS-$(CONFIG_JPEG2000_ENCODER)        += j2kenc.o mqcenc.o mqc.o jpeg2000.o \
-                                          jpeg2000dwt.o jpeg2000dsp.o
-OBJS-$(CONFIG_JPEG2000_DECODER)        += jpeg2000dec.o jpeg2000.o      \
+                                          jpeg2000dwt.o
+OBJS-$(CONFIG_JPEG2000_DECODER)        += jpeg2000dec.o jpeg2000.o jpeg2000dsp.o \
                                           jpeg2000dwt.o mqcdec.o mqc.o
 OBJS-$(CONFIG_JPEGLS_DECODER)          += jpeglsdec.o jpegls.o
 OBJS-$(CONFIG_JPEGLS_ENCODER)          += jpeglsenc.o jpegls.o