QCA988X hw2.0: add firmware-5.bin_10.2.4.70.56

The OnHub team reports that starting with 10.2.4.70.54 there are fixes
that address MCS rate selection getting stuck.

See b/30712378

Change-Id: I25b1cedd1fd6b9725ece973381e650a73851af6d
diff --git a/ath10k/QCA988X/hw2.0/firmware-5.bin b/ath10k/QCA988X/hw2.0/firmware-5.bin
index 88849a2..7d88ebb 100644
--- a/ath10k/QCA988X/hw2.0/firmware-5.bin
+++ b/ath10k/QCA988X/hw2.0/firmware-5.bin
Binary files differ