power: reset: at91-reset: remove leftover platform_device_id

commit eacd8d09 ("power/reset: at91-reset: remove useless
at91_reset_platform_probe()") removed non DT probe support but forgot to
remove the now useless id_table. Do that now.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>