cmake: respect -DTESSDATA_PREFIX=/path (on linux)

Author: zdenop

cmake/Configure.cmake

@@ -123,6 +123,13 @@ file(APPEND ${AUTOCONFIG_SRC} "
 #cmakedefine HAVE_LIBARCHIVE ${HAVE_LIBARCHIVE}
 ")
 
+if(TESSDATA_PREFIX)
+ add_definitions(-DTESSDATA_PREFIX=${TESSDATA_PREFIX})
+ file(APPEND ${AUTOCONFIG_SRC} "
+#cmakedefine TESSDATA_PREFIX ${TESSDATA_PREFIX}
+")
+endif()
+
 test_big_endian(WORDS_BIGENDIAN)
 
 file(APPEND ${AUTOCONFIG_SRC} "