ath5k: Fixes for PCI-E cards

 * Fix nic_wakeup for PCI-E chips (don't set AR5K_RESET_CTL_PCI bit)

 * Fix dma size setting for PCI-E chips (thanx to Bob Copeland).

Changes-licensed-under: ISC
Signed-off-by: Nick Kossifidis <mickflemm@gmail.com>
Signed-off-by: Luis R. Rodriguez <mcgrof@winlab.rutgers.edu>
Signed-off-by: John W. Linville <linville@tuxdriver.com>