Fix suspend/resume for ums(4) and umt(4); Calling hidm*_attach not at the

Fix suspend/resume for ums(4) and umt(4);  Calling hidm*_attach not at the
end of the device driver attach function can cause accessops functions to
be called by wscons(4) *before* the device has completed its attach
procedure.  In this case this has led the device driver to ignore
interrupts after resume, because during resume ums_disable/umt_disable
were called last, *after* ums_enable/umt_enable.

OK phessler@