KVM: arm64: Fix prototype for __sve_save_state/__sve_restore_state

KVM: arm64: Fix prototype for __sve_save_state/__sve_restore_state

Since the prototypes for __sve_save_state/__sve_restore_state at
hyp were added, the underlying macro has acquired a third
parameter for saving/restoring ffr.

Fix the prototypes to account for the third parameter, and
restore the ffr for the guest since it is saved.

Suggested-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20240603122852.3923848-3-tabba@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>