power: reset: piix4: add missing MODULE_DESCRIPTION() macro

make allmodconfig && make W=1 C=1 reports:
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/power/reset/piix4-poweroff.o

Add the missing invocation of the MODULE_DESCRIPTION() macro.
Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Link: https://lore.kernel.org/r/20240608-md-drivers-power-reset-v1-1-08dbc1a546a2@quicinc.comSigned-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

drivers/power/reset/piix4-poweroff.c

@@ -106,4 +106,5 @@ static struct pci_driver piix4_poweroff_driver = {
 
 module_pci_driver(piix4_poweroff_driver);
 MODULE_AUTHOR("Paul Burton <paul.burton@mips.com>");
+MODULE_DESCRIPTION("Intel PIIX4 power-off driver");
 MODULE_LICENSE("GPL");