ath11k: change return buffer manager for QCA6390

QCA6390 firmware uses HAL_RX_BUF_RBM_SW1_BM, not HAL_RX_BUF_RBM_SW3_BM. This is
needed to fix a case where an A-MSDU has an unexpected LLC/SNAP header in the
first subframe (CVE-2020-24588).

Tested-on: QCA6390 hw2.0 PCI WLAN.HST.1.0.1-01740-QCAHSTSWPLZ_V2_TO_X86-1

Signed-off-by: Baochen Qiang <bqiang@codeaurora.org>
Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20210914163726.38604-2-jouni@codeaurora.org