misc/pvpanic: Export module FDT device table

Export the module FDT device table to ensure the FDT compatible strings
are listed in the module alias. This help the pvpanic driver can be
loaded on boot automatically not only the ACPI device, but also the FDT
device.

Fixes: 46f934c9

 ("misc/pvpanic: add support to get pvpanic device info FDT")
Signed-off-by: Shile Zhang <shile.zhang@linux.alibaba.com>
Link: https://lore.kernel.org/r/20210218123116.207751-1-shile.zhang@linux.alibaba.com
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>