KVM: arm64: Use the appropriate feature trap register for SVE at EL2 setup

KVM: arm64: Use the appropriate feature trap register for SVE at EL2 setup

Use the architectural feature trap/control register that
corresponds to the current KVM mode, i.e., CPTR_EL2 or CPACR_EL1,
when setting up SVE feature traps.

Signed-off-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230724123829.2929609-4-tabba@google.com
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>