Avoid the following checkpatch warning:

include/dt-bindings/clock/imx8mm-clock.h:284: check: Please don't use
 multiple blank lines
Signed-off-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>