doc: clock_control/stm32f1: Fix @file tag

The @file tag should follow by a file (or nothing for current file),
instead of file description. Fix it by separating the description.

Change-Id: Iabe3550568cdfdda6ad71be6fab3e8b5dfbeb940
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
1 file changed