doxygen: Fix many warnings

This commit fixes nearly all of the reported doxygen warnings.

I tried to not clutter the log with removed trailing spaces.
Removed whitespace and converted tab/spaces for all files affected by this commit
are in a separate branch.

cpu/mc1322x/lib/printf.c

@@ -34,7 +34,7 @@
  */
 
 /**
- * \file printf-stdarg.c
+ * \file lib/printf.c
  *
  * \brief sprintf functions to replace newlib for AVR32 UC3.
  *