enable RANDOMIZE_BASE

this is enabled in the mainline arm64 defconfig and Debian kernels;
see https://lwn.net/Articles/444556/ for details

Signed-off-by: Martin Kepplinger <martin.kepplinger@puri.sm>
2 jobs for config_randomize_kmem in 46 minutes and 39 seconds (queued for 2 seconds)
latest
Status Job ID Name Coverage
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passed #270789
librem5
build:aarch64

00:13:44

passed #270790
librem5:arm64
build:deb

00:46:37