soc: marvell: hw_access: cleaning up existing hw access driver

commit adbcb6468ec08e2e43a4d246c46b3d629fe8e72a from
git@git.assembla.com:cavium/WindRiver.linux.git

1. Defining ioctls using standard way
2. Code cleanup, defined static function for handling ioctl cmds.
3. Avoid camel case

Change-Id: I6701eaca5e6068e3b671c903177227421153df5e
Signed-off-by: Harman Kalra <hkalra@marvell.com>
Reviewed-on: https://sj1git1.cavium.com/c/IP/SW/kernel/linux/+/55860
Tested-by: sa_ip-sw-jenkins <sa_ip-sw-jenkins@marvell.com>
Reviewed-by: Sunil Kovvuri Goutham <sgoutham@marvell.com>
Signed-off-by: Ruiqiang Hao <Ruiqiang.Hao@windriver.com>