ath79: base-files: fix broken network config

ath79: base-files: fix broken network config

Fix bash syntax error introduced in commit cce2e8db564b ("ath79: add
support for TP-Link TL-WR941HP v1") which resulted in broken default
network configuration.

 In target/linux/ath79/generic/base-files/etc/board.d/02_network line 402:
	tplink,tl-wr842n-v2)\
        ^-- SC1073: Couldn't parse this case item. Fix to allow more checks.

References: https://gitlab.com/ynezz/openwrt-device-runtime-testing/-/jobs/1398837698/artifacts/file/cram-result-archer-c7-v5-initramfs.txt
Fixes: cce2e8db564b ("ath79: add support for TP-Link TL-WR941HP v1")
Signed-off-by: Petr Štetiar <ynezz@true.cz>