Force core_version to be added to compiled binary

Author: igrr

tools/sdk/ld/eagle.app.v6.common.ld

@@ -18,6 +18,7 @@ EXTERN(_DoubleExceptionVector)
 EXTERN(_KernelExceptionVector)
 EXTERN(_NMIExceptionVector)
 EXTERN(_UserExceptionVector)
+EXTERN(core_version)
 PROVIDE(_memmap_vecbase_reset = 0x40000000);
 /* Various memory-map dependent cache attribute settings: */
 _memmap_cacheattr_wb_base = 0x00000110;