qemu-timer: Fix limits for w32 mmtimer

timeSetEvent only accepts delays in the range which is returned by
timeGetDevCaps.

The lower limit is typically 1 (= 1 ms), so the constant value of 1
in the old code usually worked.

The upper limit can be as low as 10000 ms, so the latest changes in
QEMU's timer handling which introduced timeout values above that limit
could result in failures of timeSetEvent when the timer was re-armed.

Signed-off-by: Stefan Weil <sw@weilnetz.de>
