docs: driver-api: Remove trailing blank line

There's no use for this blank line at the end of the file. Remove it.
Signed-off-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

Documentation/driver-api/miscellaneous.rst

@@ -47,4 +47,3 @@ used by one consumer at a time.
 
 .. kernel-doc:: drivers/pwm/core.c
    :export:
-