ANDROID: input: keyreset: switch to orderly_reboot

Prior restart function would make a call to sys_sync and then
execute a kernel reset.  Rather than call the sync directly,
thus necessitating this driver to be builtin, call orderly_reboot,
which will take care of the file system sync.

Note: since CONFIG_INPUT Kconfig is tristate, this driver can be built
as module, despite being marked bool.

Signed-off-by: Eric Ernst <eric.ernst@linux.intel.com>