KVM: arm64: Enable Cortex-A510 erratum 2077057 by default

The recently added configuration option for Cortex A510 erratum 2077057 does
not have a "default y" unlike other errata fixes. This appears to simply be
an oversight since the help text suggests enabling the option if unsure and
there's nothing in the commit log to suggest it is intentional.

Fixes: 1dd498e5

 ("KVM: arm64: Workaround Cortex-A510's single-step and PAC trap errata")
Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220225184658.172527-1-broonie@kernel.org