Enable CONFIG_HZ_1000

According to upstream "1000 Hz is the preferred choice for desktop systems and other systems requiring fast interactive responses to events." It looks like Debian is an outlier defaulting to 250 Hz. This was added in 0c0dffcb in 2006. Unfortunately the reason for this decision does not seem to be documented.

The Linux mainline amd64 defconfig specifies CONFIG_HZ_1000 since 2008: https://github.com/torvalds/linux/commit/5cb04df8d3f03e37a19f2502591a84156be71772

I have also checked other distribution configurations to see what they are doing. Fedora seems to default to 1000 Hz since at least the first commit in https://src.fedoraproject.org/rpms/kernel/tree/rawhide which was in 2010. Nowadays all archs seem to use 1000 Hz. Ubuntu switched recently but also default to 1000 Hz everywhere now. Related discussion in https://github.com/torvalds/linux/commit/5cb04df8d3f03e37a19f2502591a84156be71772

Assuming the Debian config primarily targets desktop and server sized systems and this should make everything a little snappier I think it would make sense to follow the trend and switch back to 1000 Hz too.