staging: sm750fb: Add void to function definition with no arguments

Found by checkpatch.pl - ERROR: Bad function definition

A function with no arguments allows for variadic arguments. Add
void in between the empty parentheses to indicate that the function
takes no arguments.

changes made using coccinelle script:
@@
type T;
identifier f;
@@
T f(
+void
 ) {
...
}

Signed-off-by: Supriya Karanth <iskaranth@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>