PS/2 mouse device probing costs more than 600ms after mouse driver
was initialized.
To compile it as modules can make the probing parallel with
init(systemd) startup, which can save about 600ms startup time.
Signed-off-by: NShile Zhang <shile.zhang@linux.alibaba.com>
Acked-by: NJoseph Qi <joseph.qi@linux.alibaba.com>