input: misc: pat9125: fix issues found in static analysis

Fix the following issues found in static analysis:
- missing blank lines after declarations
- unnecessary return in a void function
- exporting world writable files is usually an error
- block comments use * on subsequent and trailing lines
- Add DT binding description and vendor prefixe for the
driver.
- Add Linux Foundation copyright markings.

Change-Id: Id2ed9a6d4e31bd2acd3185bf7ef9c78f8a41cf36
Signed-off-by: Himanshu Aggarwal <haggarwa@codeaurora.org>
Signed-off-by: Vevek Venkatesan <vevekv@codeaurora.org>
Signed-off-by: Shantanu Jain <shjain@codeaurora.org>