kernel: add CONFIG_KEYS=y to enable kernel keyring

KinD checks for the presence of this (and other) kernel configuration
via scripts like
https://blog.hypriot.com/post/verify-kernel-container-compatibility/ or
attempts to directly use /proc/sys/kernel/keys/ without checking to see
if it exists, causing an exit when it does not see it.

Docker/it's consumers apparently expect to be able to use the kernel
keyring and it's associated syscalls from/for containers.

There aren't any known downsides to enabling this except that it would
by definition enable additional syscalls defined in
https://man7.org/linux/man-pages/man7/keyrings.7.html which are
reachable from userspace. This minimally increases the attack surface of
the Kata Kernel, but this attack surface is minimal (especially since
the kernel is most likely being executed by some kind of hypervisor) and
highly restricted compared to the utility of enabling this feature to
get further containerization compatibility.

Signed-off-by: Crypt0s <BryanHalf@gmail.com>

tools/packaging/kernel/configs/fragments/common/base.conf

@@ -41,6 +41,8 @@ CONFIG_RELOCATABLE=y
 # https://github.com/kata-containers/tests/issues/1543
 # RANDOM_TRUST_CPU=y
 
+CONFIG_KEYS=y
+
 # CONFIG_CGROUP_PERF needs
 CONFIG_HAVE_PERF_EVENTS=y
 CONFIG_PERF_EVENTS=y

tools/packaging/kernel/kata_config_version

@@ -1 +1 @@
-139
+140