Decoder: Added sample decoder config file to be used with avcdec

avcdec takes command line arguments and as well as supports passing arguments
through a config file

Change-Id: Icc1dec3f735f89d510f548641896b7cfac676a2b

test/decoder/dec.cfg

@@ -0,0 +1,12 @@
+--input input.h264
+--save_output 0
+--num_frames -1
+--output out.yuv
+--chroma_format YUV_420P
+--share_display_buf 0
+--num_cores 3
+--loopback 0
+--display 0
+--fps 59.94
+--arch ARM_A9Q
+--soc GENERIC