net: Add missing TST_CFG_WRITE bits around sky2_pci_write

Add missing TST_CFG_WRITE bits around sky2_pci_write*() in Optima
setup routines.  Without the cfg-write bits, the driver may spew endless
link-up messages through qlink irq.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>