KVM: arm64: pkvm: Don't mask already zeroed FEAT_SVE

FEAT_SVE is already masked by the fixed configuration for
ID_AA64PFR0_EL1; don't try and mask it at runtime.

No functional change intended.

Signed-off-by: Oliver Upton <oupton@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220509162559.2387784-3-oupton@google.com