arm64: dts: qcom: sc7280: Add WCN6750 WiFi node

Add DTS node for WCN6750 WiFi chipset.

Signed-off-by: Manikanta Pubbisetty <quic_mpubbise@quicinc.com>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220406111303.27670-1-quic_mpubbise@quicinc.com