[U-Boot] rockchip: timer: fix U_BOOT_DRIVER name

[Philipp Tomsich]

> When I originally added this driver, I did some careless (and in
> retrospect: mindless) copy & paste for the U_BOOT_DRIVER structure
> skeletion... unfortunately, the 'arc_timer' string was committed
> and slipped through all reviews.
> 
> This fixes the U_BOOT_DRIVER name to read 'rockchip_rk3368_timer'
> (as originally intended).
> 
> Signed-off-by: Philipp Tomsich <philipp.tomsich at theobroma-systems.com>
> Reported-by: Artturi Alm <artturi.alm at gmail.com>
> Reviewed-by: Simon Glass <sjg at chromium.org>
> ---
> 
>  drivers/timer/rockchip_timer.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 

Applied to u-boot-rockchip, thanks!