fips-mode-setup: Enable FIPS system-wide crypto policy.

[hoodedvul]

Take into account the main readme for this section. README first.

$ sudo fips-mode-setup --enable
Kernel initramdisks are being regenerated. This might take some time.
Setting system policy to FIPS
Note: System-wide crypto policies are applied on application start-up.
It is recommended to restart the system for the change of policies
to fully take place.
FIPS mode will be enabled.
Please reboot the system for the setting to take effect.

Warning: Using 'update-crypto-policies --set FIPS' is not sufficient for
         FIPS compliance.
         Use 'fips-mode-setup --enable' command instead.

Verify after reboot.

$ sudo fips-mode-setup --check
FIPS mode is enabled.