[FS#621] Update QCA988X firmware

[LEDE Bugs]

The following task has a new comment added:

FS#621 - Update QCA988X firmware
User who did this - Hauke Mehrtens (Hauke)

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Could you try this firmware file instead:
https://github.com/kvalo/ath10k-firmware/raw/master/QCA9888/hw2.0/3.5.1/firmware-5.bin_10.4-3.5.1-00014
It is also used in linux-firmware, but I do not have a device to test.

cd /lib/firmware/ath10k/QCA9888/hw2.0/
wget http://github.com/kvalo/ath10k-firmware/raw/master/QCA9888/hw2.0/3.5.1/firmware-5.bin_10.4-3.5.1-00014
mv firmware-5.bin firmware-5.bin-old
mv firmware-5.bin_10.4-3.5.1-00014 firmware-5.bin
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More information can be found at the following URL:
https://bugs.lede-project.org/index.php?do=details&task_id=621#comment3604