doc: replace @return by Return:

Sphinx expects Return: and not @return to indicate a return value.

find . -name '*.c' -exec \
sed -i 's/^\(\s\)\*\(\s*\)@return\(\s\)/\1*\2Return:\3/' {} \;

find . -name '*.h' -exec \
sed -i 's/^\(\s\)\*\(\s*\)@return\(\s\)/\1*\2Return:\3/' {} \;

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
diff --git a/arch/x86/cpu/broadwell/pch.c b/arch/x86/cpu/broadwell/pch.c
index f012db9..37fcddb 100644
--- a/arch/x86/cpu/broadwell/pch.c
+++ b/arch/x86/cpu/broadwell/pch.c
@@ -522,7 +522,7 @@
 /**
  * pch_serialio_init() - set up serial I/O devices
  *
- * @return 0 if OK, -ve on error
+ * Return: 0 if OK, -ve on error
  */
 static int pch_serialio_init(void)
 {