MFC: r233580

MFC:	r233580

- Do not clobber softc when psm(4) is reintialized.
- Make INITAFTERSUSPEND flag independent of HOOKRESUME flag.
- Automatically set INITAFTERSUSPEND flag when ALPS GlidePoint is detected.
- Always probe Synaptics Touchpad.  Allow MOUSE_SYN_GETHWINFO ioctl and
automatically set INITAFTERSUSPEND flag when a supported device is detected,
regardless of "hw.psm.synaptics_support" tunable setting.
- Update psm(4) to reflect the above changes.
- Remove long-time defunct SYNCHACK flag while I am in the neighborhood.

git-svn-id: svn://svn.freebsd.org/base/stable/9@234713 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f