input: touchscreen: Goodix gt915 driver cleanup

Cleanup the gt915 goodix driver from checkpatch failures.
Also have cleared the checkpatch errors on 3.18

  This patch is propagated from 3.4 kernel
    commit: 930d66c61cf5bd49bbfbd064b1e51955fdef1eb9
    input: touchscreen: Goodix gt915 driver cleanup

Change-Id: Id841423f229b6abc674cc1e3c6441d55062b6ab4
Signed-off-by: Shantanu Jain <shjain@codeaurora.org>
Signed-off-by: Bingzhe Cai <bingzhec@codeaurora.org>
Signed-off-by: Sudhakar Manapati <smanap@codeaurora.org>