ar71xx: Remove ath10k packages from archer-c7-v1 (fixes FS#1743)

ath10k_pci driver crashes once loaded and causes boot loops on this
device as 5GHz radio QCA9880-AR1A shipped with this router is broken.
It's not possible to fix this problem in software, miniPCIe radio has to
be replaced.

We could've probably fixed crashing of the ath10k driver by reverting
following upstream commit:

 commit 1a7fecb766c83dace747f42b25bbb544b00a0163
 Author: Michal Kazior <michal.kazior@tieto.com>
 Date:   Sat Jan 24 12:14:48 2015 +0200

    ath10k: reset chip before reading chip_id in probe

but it's not worth the effort as it wouldn't make that 5GHz radio usable
anyway. So it seems more convenient to just remove the crashing driver
and provide bootable images, as I believe, that a router that is working
but degraded is better than a router that will not work.

For details please see discussions in PR[1] and in FS#1743[2].

1. https://github.com/openwrt/openwrt/pull/1349
2. https://bugs.openwrt.org/index.php?do=details&task_id=1743

Reviewed-by: Stefan Lippers-Hollmann <s.l-h@gmx.de>
Signed-off-by: Aubrey McIntosh, PhD <aubrey.mcintosh@utexas.edu>
[subject and commit message tweaks]
Signed-off-by: Petr Štetiar <ynezz@true.cz>

target/linux/ar71xx/image/generic-tp-link.mk

@@ -87,7 +87,7 @@ TARGET_DEVICES += archer-c5-v1
 define Device/archer-c7-v1
   $(Device/tplink-8mlzma)
   DEVICE_TITLE := TP-LINK Archer C7 v1
-  DEVICE_PACKAGES := kmod-usb-core kmod-usb2 kmod-usb-ledtrig-usbport kmod-ath10k ath10k-firmware-qca988x
+  DEVICE_PACKAGES := kmod-usb-core kmod-usb2 kmod-usb-ledtrig-usbport
   BOARDNAME := ARCHER-C7
   DEVICE_PROFILE := ARCHERC7
   TPLINK_HWID := 0x75000001