staging: imx-drm: remove unnecessary braces

Fix checkpatch warning by removing unnecessary braces.
Compile-tested the single file.

Signed-off-by: Sima Baymani <sima.baymani@gmail.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Reviewed-by: Archana Kumari <archanakumari959@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>