New to OpenWRT and recently installed OpenWRT 18.06.1 on a TP-Link Archer C7 V2. Just curious as to why a Qualcomm Atheros QCA9880 802.11nac wireless driver was installed for 5GHz but the Qualcomm Atheros driver was not for the 2.4 GHz? The driver shows as a Generic MAC80211 802.11bgn.
netifd only knows about the PCI IDs of a subset of wlan cards, but the visual representation is merely cosmetics and bears no functional features; for supported devices it doesn't explicitly know about, the default label is "Generic MAC80211 802.11bgn" device.
The TP-Link Archer C7 V2 has two wlan cards, the 2.4 GHz card is part of the chipset and driven by ath9k - only the 5 GHz card is based on QCA9880-BR4A and driven by ath10k(-ct).
Per the Techdata pages for both version 1 and version 2, your WiFi chip uses ath10k. So, it should be possible to install the ath10k-ct driver; but completely unnecessary to do so.