Input: sun4i-lradc-keys - add wakeup support

Allow the driver to wake the system on key press if the "wakeup-source"
property is provided in the device tree. Using the LRADC as a wakeup
source requires keeping the AVCC domain active during sleep. Since this
has a nontrivial impact on power consumption (sometimes doubling it),
disable the LRADC wakeup source by default.

Signed-off-by: Ondrej Jirman <x@xff.cz>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Samuel Holland <samuel@sholland.org>
Link: https://lore.kernel.org/r/20220424161328.61103-1-samuel@sholland.org


Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>