[PATCH] clocksource/drivers/fttmr010: fix set_next_event handler

[Lei YU]

> >
> > Make sense. I actually booted up kernel on qemu-palmetto (ast2400) but I'm doubting if test is valid because it depends on how qemu emulates the hardware. It would be great if someone can help to verify the patch on physical ast2400.
>
> I gave this a spin on the ast2400. It looked okay, but I was wondering
> if you could share you test case so I can run the same test?

Tested on Palmetto (OpenPOWER P8 with AST2400), and it does show the fix is
working on AST2400 as well.
Without the patch, usleep(100) takes tens of milliseconds randomly;
With the patch, usleep(100) takes about 600~700 microseconds stably.

Tested-by: Lei YU <mine260309 at gmail.com>