Add wmv2 dependency to vc1 compilation.

Fixes compilation with --disable-everything --enable-decoder=vc1.

libavcodec/Makefile

@@ -445,7 +445,7 @@ OBJS-$(CONFIG_VB_DECODER)              += vb.o
 OBJS-$(CONFIG_VBLE_DECODER)            += vble.o
 OBJS-$(CONFIG_VC1_DECODER)             += vc1dec.o vc1.o vc1data.o vc1dsp.o \
                                           msmpeg4dec.o msmpeg4.o msmpeg4data.o \
-                                          intrax8.o intrax8dsp.o
+                                          intrax8.o intrax8dsp.o wmv2dsp.o
 OBJS-$(CONFIG_VCR1_DECODER)            += vcr1.o
 OBJS-$(CONFIG_VMDAUDIO_DECODER)        += vmdav.o
 OBJS-$(CONFIG_VMDVIDEO_DECODER)        += vmdav.o