qemu-options.hx: Fix reversed description of icount sleep behavior

The documentation for the -icount option incorrectly describes the behavior
of the sleep suboption. Based on the actual implementation and system
behavior, the effects of sleep=on and sleep=off were inadvertently reversed.
This commit updates the description to reflect their intended functionality.

Cc: qemu-stable@nongnu.org
Fixes: fa647905e6 ("qemu-options.hx: Fix minor issues in icount documentation")
Signed-off-by: Ethan Chen <ethan84@andestech.com>
Message-id: 20250606095728.3672832-1-ethan84@andestech.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

qemu-options.hx

@@ -4936,13 +4936,13 @@ SRST
     with actual performance.
 
     When the virtual cpu is sleeping, the virtual time will advance at
-    default speed unless ``sleep=on`` is specified. With
-    ``sleep=on``, the virtual time will jump to the next timer
+    default speed unless ``sleep=off`` is specified. With
+    ``sleep=off``, the virtual time will jump to the next timer
     deadline instantly whenever the virtual cpu goes to sleep mode and
     will not advance if no timer is enabled. This behavior gives
     deterministic execution times from the guest point of view.
-    The default if icount is enabled is ``sleep=off``.
-    ``sleep=on`` cannot be used together with either ``shift=auto``
+    The default if icount is enabled is ``sleep=on``.
+    ``sleep=off`` cannot be used together with either ``shift=auto``
     or ``align=on``.
 
     ``align=on`` will activate the delay algorithm which will try to