MIPS: ath79: update copyright headers of PCI related files

Add copyright records according to the recent changes in
the PCI code. Also fix up the descriptions.

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: Imre Kaloz <kaloz@openwrt.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/3503/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>