Added TegraJPEG supporting for TK1 L4T r21.5.

add downloading tegra jpeg at L4T r21.5.
you also can download the file from http://developer.download.nvidia.com/embedded/L4T/r21_Release_v5.0/source/gstjpeg_src.tbz2 to folder ${srouce_root}/depends/gstjpeg/

Author: xiekuncn

cmake_modules/FindTegraJPEG.cmake

@@ -37,6 +37,8 @@ IF(TegraJPEG_IS_L4T)
     SET(L4T_GSTJPEG_URL_PART r21_Release_v3.0/sources)
   ELSEIF(L4T_VER MATCHES ^21.4)
     SET(L4T_GSTJPEG_URL_PART r21_Release_v4.0/source)
+  ELSEIF(L4T_VER MATCHES ^21.5)
+    SET(L4T_GSTJPEG_URL_PART r21_Release_v5.0/source)  
   ELSEIF(L4T_VER MATCHES ^23.1)
     SET(L4T_GSTJPEG_URL_PART r23_Release_v1.0/source)
   ELSEIF(L4T_VER MATCHES ^23.2)