staging: unisys: visorinput: re-order declarations for consistency

In order to be more consistent with kernel conventions used elsewhere,
I have re-ordered declarations in visorinput.c to follow this general
order (where possible):
* #defines
* struct/enum/union declarations
* static declarations (const if possible for all of them)
* forward function declarations where absolutely necessary

Exceptions were made for the static declarations like the driver
declaration, given that it depends on previously-defined callbacks.
So such declarations are at the end of visorinput.c.

Signed-off-by: Tim Sell <Timothy.Sell@unisys.com>
Signed-off-by: Benjamin Romer <benjamin.romer@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>